Check Engine Light again

My check engine light is on. My ³not a dealer² mechanic says that the code(s) that he reads define one of two possible repairs bith pricey. He suggested that I see a dealer so that if the dealer guesses wrong I will be pissed off at the dealer and not him.

I went to AutoZone and read the codes. Their ³meter² says that 4 codes are involved but when I get the numbers two of them repeat. The codes that come back are:

P0171 System too lean (Bank 1) P0174 System too lean (Bank 2) P0171 System too lean (Bank 1) P0174 System too lean (Bank 2)

Responses to posts on this code suggest replacing the O2 sensor. One respondent questions whether both would go out at the same time.

I guess the next question is whether I should replace both of the pre catalytic converter sensors first or the post catalyåtic converter sensor first.

The dealer quoted $225 each for the pre coverter sensors and 128.80 for the post converter sensor plus $166 labor if all three are needed.

After market pre catalytic sensors sell for $78.81 at Autozone, post converter sensors are special order

I am just outside the 5 year emissions warrenty period but only have 46K miles. Anyone know of a special warrenty extension.

Note that I have an 01 Sienna with a V6 engine which I believe is the same engine that is in the Camry V6 (there is no Sienna newsgroup). My check engine light is on. My ³not a dealer² mechanic says that the code(s) that he reads define one of two possible repairs bith pricey. He suggested that I see a dealer so that if the dealer guesses wrong I will be pissed off at the dealer and not him.

I went to AutoZone and read the codes. Their ³meter² says that 4 codes are involved but when I get the numbers two of them repeat. The codes that come back are:

P0171 System too lean (Bank 1) P0174 System too lean (Bank 2) P0171 System too lean (Bank 1) P0174 System too lean (Bank 2)

Responses to posts on this code suggest replacing the O2 sensor. One respondent questions whether both would go out at the same time.

I guess the next question is whether I should replace both of the pre catalytic converter sensors first or the post catalyåtic converter sensor first.

The dealer quoted $225 each for the pre coverter sensors and 128.80 for the post converter sensor plus $166 labor if all three are needed.

After market pre catalytic sensors sell for $78.81 at Autozone, post converter sensors are special order

I am just outside the 5 year emissions warrenty period but only have 46K miles. Anyone know of a special warrenty extension.

Note that I have an 01 Sienna with a V6 engine which I believe is the same engine that is in the Camry V6 (there is no Sienna newsgroup).

Reply to
Avrum Lapin
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The chances that both 02 sensors failed are slim; it looks like a vacuum leak because both banks are lean. You need a good shop to look at this, at this point they need to read the ecu's data i.e. long term and short term fuel trims, and what is the o2 sensors doing.

Reply to
Stephen H

Yeah, I agree strongly with StephenH. The only thing these codes indicate is a lean condition in the engine (or a percieved lean condition by the engine computer). If one or more of the 02 sensors were at fault, you would probably have additional codes set. The only component here that could cause both of these codes would be the mass airflow sensor (MAF), but that is no reason to haul off and replace it. You need to find a good technician with a handle on EFI systems and the ability to interpret an engine data list.

Reply to
qslim

Same problem with a 1999 Camry CE. Light comes on when the air temp or pressure changes, then goes out later. I have been told this is due to the gas cap so I just let it be. Car runs fine.

Reply to
Norman Rowe

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