I have two codes for either the MAF or the oxygen sensor and the MAF has been replaced and the car ran better but I still have the codes. So I am gonna tackle the two front oxygen sensors. Tbe codes for anyone that cares are p0171 and p0174. Anyone got any tips for the front sensors for removal. I am going to borrow a couple of oxygen sensor sockets from work tomorrow to aid in removal. Particularly help with the passenger side. The car is a 98 GT if it matters. Thanks



Mike

 

bump

 

i wouldn't replace the sensors just yet, what kind of symptoms are you experiencing? does the car run bad? my guesss is there's a vacuum leak somewhere after the MAF, so un-metered air is getting in, hence the lean codes. check all the hosesfor for any loose connections

 

I have checked over the hoses and there isnt any leaks. Car runs good also, just cant get the engine light to stay off. Isnt there usually idle problems associated with a vacuum leak and unmetered air?

 

did you reset the computer?

 

Yes there usually is if it starts to mess with the timing.

Have you tried to clean the MAF sensor? That's another possible concern. While there are no leaks, if it has oil from say a K&N or just dirt it could cause issues.

 

Its a brand new maf sensor and i havent touched the JLT air filter since i put it on.

 

Have you tried the old trick of spraying carb cleaner around the intake in search of leaks?
also with the codes p0171 and p0174 is lean bank one and two . nothing to do with the 02
sensors. now if you have a scan tool with real time sensor readings. watch the o2 sensors and
see how there switching. The fuel trims are obviously gonna be high. but while driving they still
should switch normally. If its a higher mileage engine i would look intake the intake gaskets possibly.

 

If nothing else, and you want to try replacing them, my suggestion is to just drop the midpipe and remove them with a big wrench. There's very little space up there for an O2 sensor wrench, and mine were VERY tight. To drop the midpipe you'll need a 15mm deep wellsocket, about 9-12" of extensions, and a swivel... a breaker bar wouldn't hurt things. If you have those, you can have the midpipe out in no time.

 

Hold off with changing or messing with your O2's. Clear the codes with a programmer or by disconnecting the neg. bat. cable for 30 mins or so. When was the last time you changed your fuel filter? That will cause an obvious lean condition on both banks.What are you running for an air filter? An over oiled air filter will throw those codes. Use less oil and re-clean your MAF sensor with electronics cleaner. You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration. Give those suggestions a try before you start replacing parts on your car that do not need replacement.

To do it right, you really need anOBD II scanner with data logging capabilities to find out what the short term fuel trims are doing to throw a lean code among monitoring many other variables.