Exhaust/Emissions air-fuel sensor question 1997 Camry 4cyl

[reddgreen]

Took my 1997 Camry, 2.2, auto, to the dealer to diagnose check engine light. They called me at work, said the front pipe, mid pipe, and air-fuel sensor, and air temp sensor would all have to be replaced, total over $3,200.00. Can't afford that.

They said leaks in the exhaust manifold killed the sensor.

I got some penetrating oil, got the covers off the exhaust manifold and the air-fuel sensor was loose! And I can not find a hole or crack anywhere. The welds and bolts are shiny!

I found air-fuel sensor on Amazon, for about $135.00

Is the air-fuel sensor common to go out on these cars? I have the ability to replace it (tools), but is there something else I have to do/adjust?

Also, the dealer said that the air temp sensor was 400.00. I can't find any reference to a part that expensive. I found one online that said "air temp sensor" for $40.00 range. Is this right? Did I get the wrong part?

Any help greatly appreciated.
Thanks,
Mike

[BMR]

Originally Posted by reddgreen

Is the air-fuel sensor common to go out on these cars? I have the ability to replace it (tools), but is there something else I have to do/adjust?

Yes, it's fairly common. And nope, no need to do anything else. The check engine light should reset itself, assuming that's all that was wrong. If it doesn't, you can pull & reseat the EFI fuse in the fusebox under the hood to reset it. Did the dealer tell you what the error codes were?

Also, the dealer said that the air temp sensor was 400.00. I can't find any reference to a part that expensive. I found one online that said "air temp sensor" for $40.00 range. Is this right? Did I get the wrong part?

I'm not aware of more than one air temperature sensor, so I don't think you've got it wrong. But then again, I'm not that familiar with the 4 cylinder motor, since I don't have one. Maybe someone else can chime in and confirm?

[xpeed]

That price sounds about right. There about five different brands that offers these sensors from $35-$85.

I usually get most of my OEM quality parts here.

http://www.autopartswarehouse.com/se...:IAT+Sensor%29

[BMR]

It wouldn't be the first time I've heard that the Toyota part was 10X the price of aftermarket. I remember the first time I replaced the Camry's radiator in 2001 or thereabouts. Just for giggles I called the local Toyota dealer to check their price... $800!!! I put in a Modine for a bit less than $150, IIRC.

[Tukkus]

Originally Posted by BMR

If it doesn't, you can pull & reseat the EFI fuse in the fusebox under the hood to reset it.

Does the car have to be running to reset the EFI fuse ?

I'm asking because I just replaced an oxygen sensor on my Camry to get rid of the check engine light and would like to know if there are any other problems.

I went to Autozone and they found the code for the sensor so I could replace it but now I'm not sure how to get rid of the chech engine light so I can see if I have any other problems.

[reddgreen]

Thanks everybody for the info, and links. I guess i shouldn't be surprised that the dealer would want to replace more than is necessary. I broke out the wrenches last night soaked the heat shield bolts in penetrating oil, and got them off, without breaking a bolt. All of the welds on the exhaust manifold are shiny! I can't find a leak or a hole anyplace. The tip of the bolts holding the exhaust manifold to the middle pipe are also bright and shiny, and no apparent leaks there either. So, I got my 22mm wrench out to see how badly the Air-Fuel sensor was rusted into the exhaust manifold, and ... dang, the thing was loose! I tightened it up to stop the obvious exhaust leak until I could get a new one, and install it, and half way to work today, the check engine light went off. I've seen this before on occasion, check engine comes on and off and on... due to a flaky sensor, on some other cars, so I'll keep an eye on it, but definitely don't need a $1,600.00 exhaust manifold. Thanks again for the responses and help! Good day to you all.

[reddgreen]

Tukkus, as far as I know, the computer checks a couple of cycles, and turns off the check engine light if all's ok. Someone posted above (with a LOT more knowledge than I do!) said to pull a fuse, but I don't know which one.

[Pvt-Public]

It is the EFI fuse in the fuse block under the hood. With the engine and Key OFF remove it for 10 or 15 seconds put it back in and that's it.

[BMR]

Originally Posted by Tukkus

Does the car have to be running to reset the EFI fuse ?

I'm asking because I just replaced an oxygen sensor on my Camry to get rid of the check engine light and would like to know if there are any other problems.

I went to Autozone and they found the code for the sensor so I could replace it but now I'm not sure how to get rid of the chech engine light so I can see if I have any other problems.

DON'T do it with the engine running. I'm not sure if that would do any harm, but I wouldn't risk it. Pulling the fuse removes power from the ECU, so the engine would shut down, for sure.

[reddgreen]

Well I tuned up the engine, new spark plugs and new Toyota brand air cleaner, and replaced a few badly cracked vacuum hoses, and the check engine light went off (2 months ago). It came back again, and won't go off. The engine smells like its overheating (smells like hot metal), sluggish.

AutoZone says
- Low Fuel Pressure
- Faulty MAF/VAF
- Cylinder Misfire (I don't think so, it runs too smoothly)
- Faulty H02S/AF sensor
- Large Vacuum leak (I don't think so, I fixed all of the bad vac leaks)

Wouldn't low fuel pressure make the engine run badly? It runs very smooth except some sputtering on startup in the morning sometimes.

Should I replace the front fuel filter, and the MAF for starters, maybe the AF sensor, since total only a few hundred bucks. I have heard that the H02S goes bad on these cars, isn't it in the back of the cat? Car has 97K miles, fairly well maintained. Gas mileage stinks.

Worried that the engine will catch fire, smells like hot metal around the exhaust manifold after driving for 20 minutes or so.



Thanks!

[BamZipPow]

Sounds like yer running too lean. You need to hook up a diagnostic computer setup to monitor what's going on. Maybe something like AutoTap Express DIY since it's like $50 now...

What was the code that AutoZone pulled?

Oh...they pulled a P0171...
http://www.obd-codes.com/p0171

You definitely don't want to keep running it that way. Quick way to burn up a valve (or more).

Do a fuel pressure check to rule out the low pressure.
Ultragauge or AutoTap can show you how well yer O2 sensors are doing.
What kinda plugs do you have in there now?
Did you try the starting fluid spray around the engine bay to rule out any vacuum leaks? It would be better to use a smoke machine to determine any vacuum leaks as well.

[reddgreen]

Originally Posted by BamZipPow

Sounds like yer running too lean. You need to hook up a diagnostic computer setup to monitor what's going on. Maybe something like AutoTap Express DIY since it's like $50 now...

What was the code that AutoZone pulled?

Oh...they pulled a P0171...
http://www.obd-codes.com/p0171

You definitely don't want to keep running it that way. Quick way to burn up a valve (or more).

Do a fuel pressure check to rule out the low pressure.
Ultragauge or AutoTap can show you how well yer O2 sensors are doing.
What kinda plugs do you have in there now?
Did you try the starting fluid spray around the engine bay to rule out any vacuum leaks? It would be better to use a smoke machine to determine any vacuum leaks as well.

Thanks BamZip. I have gone through the vacuum hoses fairly carefully, there may be small leaks but nothing big. Plugs and wires are new, recent, Toyota brand, as is air filter. Maybe I'm leaning to crap in the fuel filter or fuel screen on the pump. Hope its not that. thanks for all the tips.

[reddgreen]

New PCV from Toyota as well.

[JohnGD]

Dealer prices are ridiculous. No wonder some call them stealers. Looks like they're just throwing parts out to make sure the problem (or customer ) doesn't come back.

Yeah, sounds like a System Too Lean Code. But Reddgreen should write down all the codes in case there is more than one. It can help pin point, for example, if a sensor's heater failed. What part number did you use and where did you install it?

I'd verify the failure before replacing more parts. The I4 uses a Manifold Absolute Pressure sensor, not Mass Air Flow sensor, so there is no MAF to replace.

All oxygen sensors go bad just like spark plugs do. Since you are in one of the CARB states, the upstream one should be a wide band oxygen sensor (some called Air Fuel Ratio Sensor), and the downsteam one after the main converter should be a simple heated oxygen sensor.

A faulty air temp sensor or coolant temperature sensor can mess with the mixture as well. So double check those as well. Look on the air filter box for the air temp sensor. Check rockauto.com catalog for pictures and prices, and the sticky for the latest 5% off coupon code.

Here's some more info on oxygen sensors:
http://www.boschautoparts.com/Oxygen...rOverview.aspx

And details about the different designs, in the second Q&A:
http://www.boschautoparts.com/Oxygen...rview.aspx#faq

5% off code:
RockAuto Discount Code

Consider getting your own OBD-II scanner:
eBay OBDII Scanners?

[JohnGD]

No, the engine should be stopped. Look in the fuse box under the hood, on the driver side. There should be a blue 15amp fuse. Look at the diagram under the cover to find the right one.

If the right sensor was replaced the code should go away. What code did they pull - the number? Or get your own scanner:
eBay OBDII Scanners?

Originally Posted by Tukkus

Does the car have to be running to reset the EFI fuse ?

I'm asking because I just replaced an oxygen sensor on my Camry to get rid of the check engine light and would like to know if there are any other problems.

I went to Autozone and they found the code for the sensor so I could replace it but now I'm not sure how to get rid of the chech engine light so I can see if I have any other problems.