[EDIT] Ok, so I cleaned the EGR valve with Carb cleaner and the tubing as well....
HOWEVER, I found out that my EGR modulator does not have a cap on top. There's this filter type thing sitting in the modulator and it's dirty as hell... I'm guessing that may be the culprit?
AND if that's not the case, Where could I locate the DPFE sensor because I'm just going to go down the checklist so I don't blow big money... thanks for the help guys. [end edit]
Alright, for those of you who don't know, I have a 96 Corolla with a 4AFE. My check engine light is on... so annoying. But anyways my father has a diagnostics thing where he checks what exactly is wrong with it, and he made the check engine light go away by erasing it from the computer in the car.
The problem that showed on the diagnostics thing said P0401 OBD-II Trouble Code.
Basically, it's saying that I have insufficient EGR flow. It told me that my possible solutions were
1. Clean the EGR valve/tubing of deposits
2. Replace the DPFE sensor
3. Replace EGR valve
Now, my questions for you guys are these:
1.Where could I possible find any of these items and for what price?
2. Where are all of these items located in the engine?
3. Lastly, what is the difficulty of doing this myself with the help of a couple more hands?
Thanks guys, sorry for the crap load of writing. I just mean the best for my car. It's my first one and I want to take care of it so it lasts me a while. =D I appreciate all the help I can get!
Last edited by itreflop117; 12-05-2010 at 05:40 PM.
Reason: Step by step process, need more advice and I don't want to clutter the thread.
1. There's plenty of EGR parts on eBay. EGR parts aren't cheap, you're looking at anywhere from $60-$100 and that depends on whether or not it's been used, refurbished, etc.
2. On the driver's side of the engine, the specific area I don't know. I've looked for the EGR before myself and I can't seem to spot it. I'm pretty sure it's somewhere around the driver's side like where all the cooling sensors are, near/under the throttle area.
3. The only pain with the EGR is access. Once you get a few things out of the way it's just more unbolting.
__________________
94 Prizm LSi 1.8. Auto and still quick as hell.
The Following User Says Thank You to BoyYota For This Useful Post:
Have you ever cleaned out the inside of your intake manifold? If so, then keep chasing the problem. If not, then there could be enough gunk buildup inside the manifold, that it could throw the p0401 code. I had this same problem some years back where my check engine light came on. I got the code pulled and it was the EGR systems error code.
So I removed the EGR system, cleaned it out using brake parts cleaner, and compressed chunks of carbon out of the system. Got new vacuum hoses from toyota and buttoned her up. Reset the ECU, and the CEL came back on. So I removed the top portion of the intake manifold (first time) and I literally struck oil. The buildup was about a half inch of wet oil soaked carbon. Scaped off as much as I could with a flat head, and went to town with a wire brush and simple green.
CEL finally went away. If you need help knowing how to remove the top of the intake manifold, it is pretty easy. You have to remove the intake, undo the 4 hoses under the throttle body. Make sure you mark them with a strip of tape because some are water, and some are vacuum. Then you unclip a few harness wires, then its a few 12mm bolts, and some allen head bolts and it will come off. Don't bend the manifold gasket otherwise it won't seat well and you will have a leak.
Have you ever cleaned out the inside of your intake manifold? If so, then keep chasing the problem. If not, then there could be enough gunk buildup inside the manifold, that it could throw the p0401 code. I had this same problem some years back where my check engine light came on. I got the code pulled and it was the EGR systems error code.
So I removed the EGR system, cleaned it out using brake parts cleaner, and compressed chunks of carbon out of the system. Got new vacuum hoses from toyota and buttoned her up. Reset the ECU, and the CEL came back on. So I removed the top portion of the intake manifold (first time) and I literally struck oil. The buildup was about a half inch of wet oil soaked carbon. Scaped off as much as I could with a flat head, and went to town with a wire brush and simple green.
CEL finally went away. If you need help knowing how to remove the top of the intake manifold, it is pretty easy. You have to remove the intake, undo the 4 hoses under the throttle body. Make sure you mark them with a strip of tape because some are water, and some are vacuum. Then you unclip a few harness wires, then its a few 12mm bolts, and some allen head bolts and it will come off. Don't bend the manifold gasket otherwise it won't seat well and you will have a leak.
thanks a lot man. Do you have by any chance a picture step by step? or is there any on the internet anywhere? thanks man... i'm just scared to mess with my car and i'm only 17 so i don't wanna screw myself and having to buy a new car because i did something wrong.. thanks a lot for the help.
just follow his steps, be very careful not to break anything, and make sure everything is sealed when you put everything back together and youll be just fine.
thanks a lot man. Do you have by any chance a picture step by step? or is there any on the internet anywhere? thanks man... i'm just scared to mess with my car and i'm only 17 so i don't wanna screw myself and having to buy a new car because i did something wrong.. thanks a lot for the help.
Okay. Now I may miss a few things since I am thinking off the top of my head. And more importantly, I'm not sure if the intake manifold/throttle body design is the same between the 7A/4A motor But remember,NEVER FEAR THE RORRA!!. If your father was smart enough to pull codes, I am sure he is mechanically inclined enough to help you do the job. So lets pop the hood, and stand in front of the motor looking down. Get about 4 cans of autozone brake parts cleaner, some simple green, rubber gloves, saftey glasses, and old clothes.
1. Look at the airbox. And look at the tube attaching the airbox to the throttle body. Unhook the cruise control cables, and you will see two clamps. One on each side of the tube. Loosen those enough to where you can pull the tube off the throttle body, and the airbox. Unclip the top of the airbox and yank out the air filter, and the top portion of the airbox. This now gives you access to the throttle body. Look at the throttle cable. It is attached to this half moon shaped contraption. You can push down on this and the throttle butterfly will open. You can shine a flashlight in there and see the darkness. AKA gunk.
2. Now. You can remove the throttle body without unhooking the water/vacuum hoses. But an important culprit to your would be problem, is that the EGR system has about 3 vacuum lines that connect to the throttle body. Look on top of the throttle body and you will see 3 thin vacuum lines. Most likely you have carbon buildup from one of the lines going into thr throttle body which is causing your CEL to go off. If you have an air compressor. This makes life 1000 times easier because you can just blow/compress air into the vacuum nipples and it will blow it into the intake manifold. If you don't have an air compressor, shove that plastic hose that comes with brake parts cleaner, and spray your way through.
3. So now to remove the throttle body. It is held on by 2 12mm nuts, and 2 12mm bolts. Carefully remove those and have a magnet ready because most likely you will drop a nut into the abyss. Slide the throttle body off, and I believe you can just set it aside with the vacuum/water lines attached. Spray the back of the throttle body butterfly off with brake parts cleaner. Brush off any carbon buildup. And spray into the vacuum nipples, and clear out the passageways for the EGR vacuum going into the throttle body. PAY ATTENTION ON HOW THE THROTTLE BODY GASKET IS SET. It is easy to flip it upside down. I usually get a sharpy and write "facing outside this way up" with an arrow or something. And if you have to remove the throttle body, pay extra attention to what line goes where, and if it is vacuum, or water. Mark those lines with masking tape and write whether it is water or vacuum. And you will have to disconnect the IAC valve harness clip.
4. Now moving onto the intake manifold. You will see two vacuum lines. A fatty and a skinny. The fatty is the PCV valve hose. Just yank both of those off the intake. Use a set of pliers because they are probably held on by clamps.
5. Now. You will see 3 allen head bolts. Those are 6mm. I use a 6mm allen head socket to remove these. And there will be two 12mm nuts at the bottom of the intake manifold. Once again be areful because you will probably drop one into the abyss. Oh yeah, there will be a small vacuum line connecting the FPR (fuel pressure regulator) to the intake manifold. Just pull it off.
6. Kay now you're ready to lift off the top section intake manifold. So do it. Observe the gunk, and yell "FFFFFFFUUUUUUUUUUUUUUUUUUUUUU".
7. Now get cleaning. Use your wire brush, a flat head. Spray it down with brake parts cleaner. And I know how you 17 year old dipshits think your indestructable. So remember to wear your safety glasses otherwise that brake parts cleaner and carbon will turn you into one eyed willey real fast. I have found it easy to use a shop vacuum to suck in any puddles of brake parts cleaner and simple green. Use several rags. Clean it until you see the silver that it used to be. Clean it as good as possible.
8. After you have cleaned both sides of the intake manifold, (the top part you removed, and the bottom part that remains in the engine), the important part is seating the top part of the intake manifold on well. The metal gasket is easily bendable. You will know if it is leaking when you start the car. Because the idle will be high. Like around 1500 RPM's. So hand tighten the 3 mm allen head bolts back on the manifold, as well as the two lower 12mm nuts. Cross torque them to get a nice flat seating.
9. Now the pain in the butt part after you have torn everything apart and put everything back together. Starting the car.
You car will run like balls and wont start at first because your spark plugs will be soaked with wet brake parts cleaner, simple green, and carbon. It will take a good 7-8 tries while throttle assisting. Once you can get it running there will be blue smoke coming out of the exhaust. This is normal. You may even have to get new spark plugs, but good news is that you can get some NGK's from vatozone for $1.99 each.
10. Let the car get to normal running temps, and watch your idle to see if you have seated the intake manifold gasket well, and check under the throttle body and make sure you've got those line re-attached well.
Stand back with the Clint Eastwood stare, and hope all goes well. Disconnect your negative terminal of the battery for about 15 seconds, and reconnect it to reset your ECU.
Some people will say that you can avoid all this trouble by using a can of seafoam, and running it through a vacuum line in the intake manifold, but it is not strong enough to clean the gunk out. I have done before and after comparisons, and seafoam is only strong enough to remove light films of carbon buildup.
Okay. Now I may miss a few things since I am thinking off the top of my head. And more importantly, I'm not sure if the intake manifold/throttle body design is the same between the 7A/4A motor But remember,NEVER FEAR THE RORRA!!. If your father was smart enough to pull codes, I am sure he is mechanically inclined enough to help you do the job. So lets pop the hood, and stand in front of the motor looking down. Get about 4 cans of autozone brake parts cleaner, some simple green, rubber gloves, saftey glasses, and old clothes.
1. Look at the airbox. And look at the tube attaching the airbox to the throttle body. Unhook the cruise control cables, and you will see two clamps. One on each side of the tube. Loosen those enough to where you can pull the tube off the throttle body, and the airbox. Unclip the top of the airbox and yank out the air filter, and the top portion of the airbox. This now gives you access to the throttle body. Look at the throttle cable. It is attached to this half moon shaped contraption. You can push down on this and the throttle butterfly will open. You can shine a flashlight in there and see the darkness. AKA gunk.
2. Now. You can remove the throttle body without unhooking the water/vacuum hoses. But an important culprit to your would be problem, is that the EGR system has about 3 vacuum lines that connect to the throttle body. Look on top of the throttle body and you will see 3 thin vacuum lines. Most likely you have carbon buildup from one of the lines going into thr throttle body which is causing your CEL to go off. If you have an air compressor. This makes life 1000 times easier because you can just blow/compress air into the vacuum nipples and it will blow it into the intake manifold. If you don't have an air compressor, shove that plastic hose that comes with brake parts cleaner, and spray your way through.
3. So now to remove the throttle body. It is held on by 2 12mm nuts, and 2 12mm bolts. Carefully remove those and have a magnet ready because most likely you will drop a nut into the abyss. Slide the throttle body off, and I believe you can just set it aside with the vacuum/water lines attached. Spray the back of the throttle body butterfly off with brake parts cleaner. Brush off any carbon buildup. And spray into the vacuum nipples, and clear out the passageways for the EGR vacuum going into the throttle body. PAY ATTENTION ON HOW THE THROTTLE BODY GASKET IS SET. It is easy to flip it upside down. I usually get a sharpy and write "facing outside this way up" with an arrow or something. And if you have to remove the throttle body, pay extra attention to what line goes where, and if it is vacuum, or water. Mark those lines with masking tape and write whether it is water or vacuum. And you will have to disconnect the IAC valve harness clip.
4. Now moving onto the intake manifold. You will see two vacuum lines. A fatty and a skinny. The fatty is the PCV valve hose. Just yank both of those off the intake. Use a set of pliers because they are probably held on by clamps.
5. Now. You will see 3 allen head bolts. Those are 6mm. I use a 6mm allen head socket to remove these. And there will be two 12mm nuts at the bottom of the intake manifold. Once again be areful because you will probably drop one into the abyss. Oh yeah, there will be a small vacuum line connecting the FPR (fuel pressure regulator) to the intake manifold. Just pull it off.
6. Kay now you're ready to lift off the top section intake manifold. So do it. Observe the gunk, and yell "FFFFFFFUUUUUUUUUUUUUUUUUUUUUU".
7. Now get cleaning. Use your wire brush, a flat head. Spray it down with brake parts cleaner. And I know how you 17 year old dipshits think your indestructable. So remember to wear your safety glasses otherwise that brake parts cleaner and carbon will turn you into one eyed willey real fast. I have found it easy to use a shop vacuum to suck in any puddles of brake parts cleaner and simple green. Use several rags. Clean it until you see the silver that it used to be. Clean it as good as possible.
8. After you have cleaned both sides of the intake manifold, (the top part you removed, and the bottom part that remains in the engine), the important part is seating the top part of the intake manifold on well. The metal gasket is easily bendable. You will know if it is leaking when you start the car. Because the idle will be high. Like around 1500 RPM's. So hand tighten the 3 mm allen head bolts back on the manifold, as well as the two lower 12mm nuts. Cross torque them to get a nice flat seating.
9. Now the pain in the butt part after you have torn everything apart and put everything back together. Starting the car.
You car will run like balls and wont start at first because your spark plugs will be soaked with wet brake parts cleaner, simple green, and carbon. It will take a good 7-8 tries while throttle assisting. Once you can get it running there will be blue smoke coming out of the exhaust. This is normal. You may even have to get new spark plugs, but good news is that you can get some NGK's from vatozone for $1.99 each.
10. Let the car get to normal running temps, and watch your idle to see if you have seated the intake manifold gasket well, and check under the throttle body and make sure you've got those line re-attached well.
Stand back with the Clint Eastwood stare, and hope all goes well. Disconnect your negative terminal of the battery for about 15 seconds, and reconnect it to reset your ECU.
Some people will say that you can avoid all this trouble by using a can of seafoam, and running it through a vacuum line in the intake manifold, but it is not strong enough to clean the gunk out. I have done before and after comparisons, and seafoam is only strong enough to remove light films of carbon buildup.
wooooow thank you sooo much. a lot of information. thanks i really appreciate itt!
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