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.
it started about a month and a half 2 months ago. While driving at highway speed car started to run rough, brought it to the shop he replaced plugs, wires, and o2 sensor. Ran fine for about 2 weeks then happened again same thing, light came on, replaced MAF sensor, ran fine about 2 more weeks, happened again today. I'm going to try and solve this with out bringing it back to the shop.
Had auto zone scan the car and it's throwing: P0171 fuel system to lean bank one.
Where do I go from here? fuel filter? fuel pump? injectors?
on a possibly unrelated note, when the car came back the most recent time it seemed to have developed a "vibration" type sound that occurs occasionally, most of the time while turning best way to describe the sound it like a dremel tool (high picked "whizzing" sound) it lasts a second or 2 then goes away and seems to be coming from the front passengers side area (either wheel well or engine bay). And it seems to be more frequent since the CEL came on.
I would much appreciate any help you guys can give. Thanks!
The "whizzing" sound could be a vacuum leak -- possibly a cracked hose, which would cause the intermittent nature of the sound. Usually a vacuum leak would cause a "too lean" on both banks, 'tho, since the unmetered air is getting in at the throttle body.
When they pulled the codes, did they pull the long and short term fuel trims for both banks? If you want to DIY this, might be a good idea to grab a OBD2 scanner that can do some data capture -- seeing what the two banks are doing will really help narrow down the issue.
The "whizzing" sound could be a vacuum leak -- possibly a cracked hose, which would cause the intermittent nature of the sound. Usually a vacuum leak would cause a "too lean" on both banks, 'tho, since the unmetered air is getting in at the throttle body.
When they pulled the codes, did they pull the long and short term fuel trims for both banks? If you want to DIY this, might be a good idea to grab a OBD2 scanner that can do some data capture -- seeing what the two banks are doing will really help narrow down the issue.
I'll try to investigate the "whizzing" further, but it really sounds more "metallic" in nature although i've never heard a vacuum leak so I can't rule it out. they did not pull the fuel trim data, what would I look for if I had that info?
maybe a vacuum leak after all... I've had a small oil leak that appears to originate near the rear exhaust manifold, someone told me that a vacuum leak could result in oil leaks, is that true?
also went out and examined the "whizzing" sound further seems to be originating somewhere low in the engine compartment I can hear it best when near a wheel well. definitely metallic does not sound like escaping air, unless the air is rattling something
My guess on the wizzing sound is that it's being caused by your power steering pump, and isn't related, it might even be a PS pump hose is making the mess in the back.
maybe a vacuum leak after all... I've had a small oil leak that appears to originate near the rear exhaust manifold, someone told me that a vacuum leak could result in oil leaks, is that true?
also went out and examined the "whizzing" sound further seems to be originating somewhere low in the engine compartment I can hear it best when near a wheel well. definitely metallic does not sound like escaping air, unless the air is rattling something
I suppose vacuum problems might make a oil leak worse. In rigs of the vintage of ours, 'tho, it's usually just old oil seals.
A metallic whizzing on the passenger side could be (in order of probability):
(1) the air conditioning compressor (usually more of a rattling sound, 'tho). Easily ruled out by turning off the A/C
(2) Power steering pump. Turning the steering back and forth while listening should make it change.
(3) Water pump. Noisy water pumps aren't good, but they usually aren't on-off -- once they start getting noisy, they tend to stay that way.
(4) Oil pump. Pretty low probability -- oil pumps hardly ever fail on these guys, and they tend to be pretty quiet.
When you have a lean driveability problem you should check for what Bosch terms "false air entry". The extra air, as others mentioned, leaned out the mixture.
One professional way to check this is to use a smoke machine and see where it's leaking. Another is simply replace all the oil seals and gaskets ($ and time).
It's too bad the shop started replacing all the parts like that.
Another place to check is the engine coolant temperature sensor the ECU uses to calculate.
Quote:
Originally Posted by 98camryguy
Hey guys,
it started about a month and a half 2 months ago. While driving at highway speed car started to run rough, brought it to the shop he replaced plugs, wires, and o2 sensor. Ran fine for about 2 weeks then happened again same thing, light came on, replaced MAF sensor, ran fine about 2 more weeks, happened again today. I'm going to try and solve this with out bringing it back to the shop.
Had auto zone scan the car and it's throwing: P0171 fuel system to lean bank one.
Where do I go from here? fuel filter? fuel pump? injectors?
on a possibly unrelated note, when the car came back the most recent time it seemed to have developed a "vibration" type sound that occurs occasionally, most of the time while turning best way to describe the sound it like a dremel tool (high picked "whizzing" sound) it lasts a second or 2 then goes away and seems to be coming from the front passengers side area (either wheel well or engine bay). And it seems to be more frequent since the CEL came on.
I would much appreciate any help you guys can give. Thanks!
I suppose vacuum problems might make a oil leak worse. In rigs of the vintage of ours, 'tho, it's usually just old oil seals.
A metallic whizzing on the passenger side could be (in order of probability):
(1) the air conditioning compressor (usually more of a rattling sound, 'tho). Easily ruled out by turning off the A/C
(2) Power steering pump. Turning the steering back and forth while listening should make it change.
(3) Water pump. Noisy water pumps aren't good, but they usually aren't on-off -- once they start getting noisy, they tend to stay that way.
(4) Oil pump. Pretty low probability -- oil pumps hardly ever fail on these guys, and they tend to be pretty quiet.
AC wasn't on, the noise doesn't happen when I turn the wheel rather when I rev the engine, if I rev just right while at a stop and in neutral it will make the sound for a split second.
back to the lean fuel mixture can anyone recommend me a place to start, at this time is the consensus that a vacuum leak is the probable cause?
back to the lean fuel mixture can anyone recommend me a place to start, at this time is the consensus that a vacuum leak is the probable cause?
Possibly fuel system, too (although vacuum problems tend to be more common).
Thing is, P0171 just means that the system detected a "too lean" condition -- it doesn't say which bank, or if it's both banks. That's why I'd really like to know the fuel trims -- if both trims are biased rich (meaning both oxygen sensors are reading a lean condition, and the ECU is trying to compensate by widening the injector widths), then the problem has to be common to both banks. If the fuel trim is pretty normal on one bank, and biased rich on the other, then the problem has to be something only on that bank.
Or, you can just do like your original mechanic and just shotgun parts until you fix the problem.
Do you have a laptop with either a serial or USB port? I've used the serial-port version of the unit at http://obddiagnostics.com/index.html for few years. It ain't pretty, but it does a nice job, and the price is right. If you don't have a laptop, then the Scangauge ( http://www.scangauge.com ) is well thought of by a number of people, and it can usually be found for $150 or so at most auto parts stores. The cheaper units are, IMHO, worthless -- they can display a code or reset a code, but can't pull any diagnostic information.
Possibly fuel system, too (although vacuum problems tend to be more common).
Thing is, P0171 just means that the system detected a "too lean" condition -- it doesn't say which bank, or if it's both banks. That's why I'd really like to know the fuel trims -- if both trims are biased rich (meaning both oxygen sensors are reading a lean condition, and the ECU is trying to compensate by widening the injector widths), then the problem has to be common to both banks. If the fuel trim is pretty normal on one bank, and biased rich on the other, then the problem has to be something only on that bank.
Or, you can just do like your original mechanic and just shotgun parts until you fix the problem.
Do you have a laptop with either a serial or USB port? I've used the serial-port version of the unit at http://obddiagnostics.com/index.html for few years. It ain't pretty, but it does a nice job, and the price is right. If you don't have a laptop, then the Scangauge ( http://www.scangauge.com ) is well thought of by a number of people, and it can usually be found for $150 or so at most auto parts stores. The cheaper units are, IMHO, worthless -- they can display a code or reset a code, but can't pull any diagnostic information.
i'm done shotgunning parts thanks
Will the fuel trim info be stored in the computer and able to be pulled as soon as I plug in a scanner? or will I have to drive around to get that info. The shop i've been going to is somewhat of a friend of the family, I can probably get him to scan it for me and give me the info you request.
Will the fuel trim info be stored in the computer and able to be pulled as soon as I plug in a scanner? or will I have to drive around to get that info. The shop i've been going to is somewhat of a friend of the family, I can probably get him to scan it for me and give me the info you request.
Yup, long-term fuel trims are stored as long as the battery isn't disconnected. Short-term fuel trims change minute-to-minute, but we're not really concerned with those.
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98 camry v6 P0171 running out of ideas help!
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