3rd & 4th Generation (1992–1996 & 1997–2001)Toyota Camry Discussion for years: 1992-1996 & 1997-2001
Topics of discussion range from fuel economy, safety, modifications, performance all involving America's favorite family car, the Toyota Camry.
I just wanted to update, for future or existing TN'ers searching for remedies to the P0420 code. I replaced my front (upstream) oxygen sensor a few weeks ago, but yesterday I finally put in the new rear (downstream) sensor. So far P0420 has not returned, but I'll know for sure within the next two or three days if it's gone for good. I purchased Denso's from RockAuto... the ones that come with connectors. I haven't driven enough yet to notice any increase in gas mileage, but that too will be found out before too long.
Removing the driver's seat wasn't necessary to reach the connector through the hole in the carpet. But removing the four bolts holding the seat down, and moving the seat back about a foot made it a lot easier.
I was wondering though... I've read about a air/fuel ratio sensor. I thought the o2 sensors controlled the air/fuel ratio. What does this sensor do? And does it generally stay free of contamination like the o2 sensors are exposed to?
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2000 Toyota Camry LE (Japan made) i4 5S-FE 367,000+ miles.
On the non-California-spec 2000 Camrys, the front (pre-cat) O2 sensor does indeed control (well, it's the primary monitor, anyhow) A/F ratio. Cali spec cars use a different front sensor that gives a more accurate reading of the A/F ratio -- these are usually referred to as "A/F sensors" instead of just "O2 sensors". Both Cali and non-Cali spec rigs uses a garden-variety O2 sensor in the back (post-cat) to monitor catalyst efficiency.
How did you remove the sensors? What tools did you use? My 2000 Camry (140000 miles) did a CEL of P0420. I cleared it twice this week. I looked at the the sensor under the car. It dosen't look like fun to remove! Where did you buy them and what was the cost?
How did you remove the sensors? What tools did you use? My 2000 Camry (140000 miles) did a CEL of P0420. I cleared it twice this week. I looked at the the sensor under the car. It dosen't look like fun to remove! Where did you buy them and what was the cost?
I bought Denso P/N 2344137 ($76.79) for the rear, and Denso P/N 2344626 for the front ($89.79).
I believe a 20mm wrench is required to remove both. We did not have a 20mm wrench, so I used a standard size that fit very closely, and it worked.
For the front, you will need to remove the lower metal shield over the exhaust manifold. The most difficult part about getting the rear one off is that it will likely be VERY stuck. One poster used a butane torch to heat up the pipe around the sensor, causing the metal to expand, and making it easier to remove. I didn't have to do this... just extended the wrench arm a bit using a large socket to increase the torque. It did take quite some time but eventually I won.
Remember to apply the provided grease, or whatever is in those little packets, on the threading of the new sensors, to make future removal easier.
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2000 Toyota Camry LE (Japan made) i4 5S-FE 367,000+ miles.
You will probably be able to make your own by going to kragen/oreilly and buying 2 spark plug foulers. You will have to drill one of them to get the sensor to fit through it.
Also you need to have the sensor about 2 inches away, 1 inch didn't work.
An alternative solution to getting your catalytic converter replaced until your car doesn't pass smog.
This should help someone.
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2000 Camry, 4 Cyl, Auto, Federal, 95k and climbing
I was wondering though... I've read about a air/fuel ratio sensor. I thought the o2 sensors controlled the air/fuel ratio. What does this sensor do? And does it generally stay free of contamination like the o2 sensors are exposed to?
How long ago did you check the valve clearances and changed timing belt? Spark plugs? Besides making sure the engine is well tuned, I'd also check for vacuum leaks, and air leaks in the exhaust system before doing the cat.
Otherwise you can replace the catalytic converter and have the P0420 come back as some owners did.
Quote:
Originally Posted by haux
Well, seems like I'm in the same boat as kento16us is/was.
Earlier tonight the P0420 reappeared.
Am I going to have to replace my rear Catalytic Converter, or could there be some other cause?
Well, seems like I'm in the same boat as kento16us is/was.
Earlier tonight the P0420 reappeared.
Am I going to have to replace my rear Catalytic Converter, or could there be some other cause?
Is P0420 the only code you're getting? A leak in the exhaust system upstream of the downstream sensor can cause a P0420 due to the excess oxygen getting into the system. Doesn't take much. I've also heard tell that sometime the catalyst get crap on it from too much low-speed city driving, and you can burn it off by taking 'er out for a nice, long highway drive. Never tried it myself, 'tho, so take it with a big grain of salt.
How long ago did you check the valve clearances and changed timing belt? Spark plugs? Besides making sure the engine is well tuned, I'd also check for vacuum leaks, and air leaks in the exhaust system before doing the cat.
Otherwise you can replace the catalytic converter and have the P0420 come back as some owners did.
What do you mean by valve clearance?
The other week I replaced the valve cover gasket, tube seals, plugs and wires all in the same day.
Timing belt was changed maybe 40-50,000 miles ago. Less than a year ago. OEM belt, too.
Regarding vacuum leaks, I've been replacing vacuum hoses as well. At least those related to the EGR system.
How would I check for air leaks in the exhaust system?
I did notice something weird a week or two ago. This is when I was wiring up my passenger seat for power. The seat was out of my car... and I took a drive to the electrical supply store. I was hearing something through the holes in the floor where the bolts go into. I don't think it was just air from driving, because when I parked, and hit the gas... I could hear it just the same. Almost sounded like air, as if the car was still in motion, when it wasn't. Could this be related?
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2000 Toyota Camry LE (Japan made) i4 5S-FE 367,000+ miles.
Is P0420 the only code you're getting? A leak in the exhaust system upstream of the downstream sensor can cause a P0420 due to the excess oxygen getting into the system. Doesn't take much. I've also heard tell that sometime the catalyst get crap on it from too much low-speed city driving, and you can burn it off by taking 'er out for a nice, long highway drive. Never tried it myself, 'tho, so take it with a big grain of salt.
The other code(s) I have gotten within the past two years are related to the EGR/EVAP system. And that is being taken care of.
A huge portion of my 336,000 miles is highway time. 2,000 mile trips within a 48 hours period is not uncommon for my vehicle, so I'm pretty sure it gets cleared out more than the common man's vehicle if that could ever be the case.
...I'm thinking I could have a leak somewhere though, as JohnGD suggested.
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2000 Toyota Camry LE (Japan made) i4 5S-FE 367,000+ miles.
The intake and exhaust valve ends' gaps to the cam lobes. Typically 8-10 mils. The gaps may widen or close. The problem is too tight a clearance. The valves don't contact the cylinder head enough to dissipate heat and they burn up. I also wondered if they don't close long enough how that affects emissions, if anyone knows.
These engines use a shim-on-bucket design that originated in 1960s VWs, which it licensed from the Italians so I heard.
Hmmm, do you plan to change the belt before the next looooong trip? How's the water pump? And pulleys? And oil seals? My guess is that the belt's stretched a bit by 50K miles. If retensioning it (no automatic tensioner here) you might as well just replace it?
Vacuum leaks: Not just vacuum hoses, but all gaskets, oil seals, PCV grommet, etc. You shouldn't see more than slightest oil in the air intake hose if at all, where the crankcase vent tube connects to it. You shouldn't see oil leaks from seals/gaskets as in over pressure.
When you check the flange connections, look for sooty signs of leaking gas. I don't know what that air-like noise might be. Could it be just engine noise? Unless you can pin point it to a pipe flange connection. Listen to another Camry too. Just beware of moving engine parts and hot exhaust.
It's also very possible it's just an aged converter that needs replacing, and nothing else. It's just that you want to rule out possible causes upstream.
Quote:
Originally Posted by haux
What do you mean by valve clearance?
The other week I replaced the valve cover gasket, tube seals, plugs and wires all in the same day.
Timing belt was changed maybe 40-50,000 miles ago. Less than a year ago. OEM belt, too.
Regarding vacuum leaks, I've been replacing vacuum hoses as well. At least those related to the EGR system.
How would I check for air leaks in the exhaust system?
I did notice something weird a week or two ago. This is when I was wiring up my passenger seat for power. The seat was out of my car... and I took a drive to the electrical supply store. I was hearing something through the holes in the floor where the bolts go into. I don't think it was just air from driving, because when I parked, and hit the gas... I could hear it just the same. Almost sounded like air, as if the car was still in motion, when it wasn't. Could this be related?
Ok, for tonight, before I go to sleep, I'm just gonna comment on the stuff I understand. ...the rest I will have to look into a bit further.
I did not plan on changing the timing belt again before I leave. I was thinking of coming back home mid-year to do it, along with the power steering pump, and give the camshaft/crankshaft seals another shot, as we were unable to remove the pulleys last time. The water pump was replaced last year with a Duralast. I was thinking maybe replacing it again with an OEM pump... and maybe replace the oil pump entirely (did gasket/seals last year too).
Oh yeah, I also replaced the PCV, grommet, and vent hose the other week. Also the hose going from the crankcase to the intake hose. I believe that's the one you're referring to that shouldn't have any oil in it. And I believe it did not. I expected it to be dirty for some reason, but it wasn't.
That ehow link is actually one I came across when doing a search. I was thinking maybe you'd have something more thorough, but I guess it's pretty straightforward. So I will give it a try within the next two days.
The noise I heard COULD be from the engine I suppose. I'll have to listen closely across that exhaust line while someone pulls the throttle.
Quote:
Originally Posted by JohnGD
The intake and exhaust valve ends' gaps to the cam lobes. Typically 8-10 mils. The gaps may widen or close. The problem is too tight a clearance. The valves don't contact the cylinder head enough to dissipate heat and they burn up. I also wondered if they don't close long enough how that affects emissions, if anyone knows.
These engines use a shim-on-bucket design that originated in 1960s VWs, which it licensed from the Italians so I heard.
Hmmm, do you plan to change the belt before the next looooong trip? How's the water pump? And pulleys? And oil seals? My guess is that the belt's stretched a bit by 50K miles. If retensioning it (no automatic tensioner here) you might as well just replace it?
Vacuum leaks: Not just vacuum hoses, but all gaskets, oil seals, PCV grommet, etc. You shouldn't see more than slightest oil in the air intake hose if at all, where the crankcase vent tube connects to it. You shouldn't see oil leaks from seals/gaskets as in over pressure.
When you check the flange connections, look for sooty signs of leaking gas. I don't know what that air-like noise might be. Could it be just engine noise? Unless you can pin point it to a pipe flange connection. Listen to another Camry too. Just beware of moving engine parts and hot exhaust.
It's also very possible it's just an aged converter that needs replacing, and nothing else. It's just that you want to rule out possible causes upstream.
__________________
2000 Toyota Camry LE (Japan made) i4 5S-FE 367,000+ miles.
The water pump was replaced last year with a Duralast. I was thinking maybe replacing it again with an OEM pump... and maybe replace the oil pump entirely (did gasket/seals last year too).
i always get toyota genuine oem part for engine/powertrain, especially for some labor intensive task, though oem parts price maybe a little higher, premature failure is pretty low unless installed incorrectly.
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