help: check engine light

[wrigley_1285]

i had same 2 codes come up multiple times. P0171 and P0174. one code is for system bank 1 lean. and the other system bank 2 lean.

the first time both these codes came up the guy at the parts store said that my MAF sensor is probably just dirty. and i got some MAF sensor cleaner. after i cleaned it i had the code cleared but it came back on within a day or so. then he said i'd need to replace the MAF, so i did(with one from the junkyard) and had the code cleared. but it came on again. however i did get the code cleared again, so far its been two days and hasn't came back on.

but i'm afraid its gonna come back on again. and when the guy cleared to code he said i need to replace my O2 sensors. both the one in front of the catalytic converter and the one after.

also i noticed my gas mileage went to sh*t. while the check engine light was on. i haven't checked my mileage since i replaced the MAF so i don't know if it's still bad or has gotten better.

 

[Cobraguy]

My god. What kind of crap do they feed folks these days?? There are several things that can pop those codes. And nothing indicates the downstream sensor should be changed. And in fact, since it's both sides, I seriously doubt it's O2 sensors at all. First things first...check for vacuum leaks.

 

[Tbars4]

...Heres my quicklist of things to check, although you may have already fixed your problem...:scratch:

A) Not the o2 sensors

1) Probably Vacuum leak
2) Clean the MAF
3) EGR tube leak
4) Plugs and wires

OR 5) Intake manifold gaskets..

 

[wrigley_1285]

thanks guys. i'll check for leaks first. and its about time for changing my plugs and wires. i know i got bosch OEM replacements wires and i think i got motorcraft plugs last time i changed them. what's your guys' suggestions for the best wires and plugs for the 4.0 OHV. i heard platinum plugs are actually the worst ones to get.

i replaced my EGR valve about 9-10 months ago, but i'll check everything again. and get some more MAF sensor cleaner. hopefully it's not a intake manifold, i don't really feel like having to do that much work with it in the cold again. i already had to replace my cv shafts, front brakes, hub assemblies, and front axle seals just a couple weeks ago. my pocket is still hurting from that.

 

[Tbars4]

...All my info is located in my signature under "Pics and Mods List"..