1997 2.8

System too lean? The car is running like it always has. Power is intermittent. lol. Going down the highway I was getting 42 mpg, but when I hit city it goes right down the drain.

The MAF was swapped out last year due to a "rough engine" code with the vag.

I don't know when the fuel filter was changed.....if ever.

I cleared the code and it hasn't come back yet.

 

Miles??? Change out the fuel filter and go from there. That is a good place to start before you start dumping cash into it . Good tune up as well if you haven't already.

 

if both fault codes p0171 and p0174 are showing suspect a maf sensor. could be faulty even though you replaced it a year ago.usually if bank one and two are set together it tends to read out maf sensor is faulty. take it to autozone they can print out the trouble code for you and on it, it will say what i just have explained. good luck

 

42 mpg????

 

Possibly a vacuum leak

 

152,000 miles. Yep 42 mpg. My scan tool figures it out by mph and gph. Usually the car has gotten 35 at best.

The car has always run a little goofy, and I thought it was running lean, I guess for a brief moment it was just enough to trip codes. So i don't think the MAF is the issue, but I can swap it out for another one.

Tune up? Whats there to do besides plugs and air filter?