Engine runs rough dashboard engine light on..

[Novice]

My 1998 Camry V6 has 110,000 miles. Every so often the engine light comes on the car runs rough as if the transmission is slipping and engine hesitation including a distinct un-burnt/burnt gas odor. My fuel consumption goes up and performance goes down.

Tuned engine and tried cleaning the throttle plate with Gumout which has not helped. Was told that there is an air/fuel sensor that needs to be replaced however that’s around $500 at the dealership.

One way that seems to make the problem go away temporary for about 50 miles or 30 miles w/AC on is by disconnecting the battery for about 30-60 seconds. This corrects the problem until the light comes back on. It seems that by opening the battery circuit resets the vehicle’s computer.

Any suggestions on what can fix the problem are greatly appreciated. Would cleaning the AIC make any difference, thanks in advance…..

[DFBonnett]

What fault code was stored in the computer?

[Novice]

AutoZone tested it, there were a few different codes when it was tested and the tech wasn’t sure which code was the culprit. Was told that the dealership can test it however it charges $175 just to diagnose the problem.

I believe some of the codes were (PO100, PO101, P1150, P1153). In order to drive without any problem I keep resetting engine’s computer by disconnecting battery.

Need to drive vehicle for around 50 miles for it to go to into problem stage. Is there a way that I can test it myself with a universal tester (what make and cost) that can also be used for other vehicles?

[Novice]

Originally Posted by DFBonnett

What fault code was stored in the computer?

Cleaned the MAP, EGR and front Oxygen sensor with contact cleaner. Wasn't able to remove the IAC since both screwheads were in rough shape. Was hoping that the problem was gone however it came back so I had it tested again today with an Actron CP9145. These are the codes that were stored in the computer.
1) PO171 - system too lean
2) P1133 - manufacturing control fuel and air metering
3) P1153 - manufacturing control fuel and air metering

Hopefully these codes cross-reference to an emissions and engine control system that can be replaced, please fire away, thanks..

[Novice]

Originally Posted by Novice

Cleaned the MAP, EGR and front Oxygen sensor with contact cleaner. Wasn't able to remove the IAC since both screwheads were in rough shape. Was hoping that the problem was gone however it came back so I had it tested again today with an Actron CP9145. These are the codes that were stored in the computer.
1) PO171 - system too lean
2) P1133 - manufacturing control fuel and air metering
3) P1153 - manufacturing control fuel and air metering

Hopefully these codes cross-reference to an emissions and engine control system that can be replaced, please fire away, thanks..

My mistake, it's MAF Mass Airflow sensor not MAP..

[DFBonnett]

From the codes it seems as if the bank 1 O2 sensor has failed. That is going to be the cylinder bank which includes is cylinder 1. That will be the bank by the firewall. I believe you will need to replace that O2 sensor as cleaning them generally does not prove efficacious.
FWIW
YMMV

[Novice]

Originally Posted by DFBonnett

From the codes it seems as if the bank 1 O2 sensor has failed. That is going to be the cylinder bank which includes is cylinder 1. That will be the bank by the firewall. I believe you will need to replace that O2 sensor as cleaning them generally does not prove efficacious.
FWIW
YMMV

Thanks, however as far as I can tell two oxygen sensors are used. The primary oxygen sensor is located in the exhaust manifold by cylinder 6 (upstream) and the secondary oxygen sensor is located after the catalytic converter (downstream). Not sure on what you mean by bank by the firewall which includes cylinder 1.

[Novice]

Originally Posted by DFBonnett

From the codes it seems as if the bank 1 O2 sensor has failed. That is going to be the cylinder bank which includes is cylinder 1. That will be the bank by the firewall. I believe you will need to replace that O2 sensor as cleaning them generally does not prove efficacious.
FWIW
YMMV

Sensor replaced and it looks like the problem is resolved, many thanks...