Check Engine Light

["Myrtle" 03P5]

So i was headed to PT this morning and my check engine light came on and i went to get it diagnosed and it said ( Fuel to lean Bank 1) or something to tht effect. so i got the light reset but it came back on so i was just wondering if that had anything to do with the O2 Sensor or if its something else. i wanted to ask ou guys first before getting rapped by someone to replace it. needless to say i trust you guys waaaaaaaaaaaaaaayyyyyyyyyyyyyyyyyy more lol

 

[i12drivemyMP5]

Well, without more info it could be several things ranging from a weak or clogging injector, fuel pump starting to go bad, coil starting to go bad, plug wire issue, worn or bad plug, vacuum leak or hose off nipple, etc etc etc

 

[MazdaSpeeder]

I had this problem in my old Thunderbird, and it was the 02 sensor. It could be several other things but I would guess that's the culprit. If it is, it's relatively inexpensive ($100 or so) for a plug and play replacement that you can install yourself in 20 minutes.

 

[bazooka joe]

often it's the o2 sensor!

 

[i12drivemyMP5]

etc etc etc = o2 sensor. Left the most obvious off the list FTL. lol

 

["Myrtle" 03P5]

would the sensor cause studdering when i accelerate. it happens then the light comes on so i wasnt shure if the sensor was the culprit or not.

 

[i12drivemyMP5]

I wouldn't think so, should just revert to the fuel mapping like after resetting ecu which shouldn't cause studdering if just a sensor issue.

 

[jdbru]

I've got the same issues on my O2 P5.

I get a code P0171

"The PCM has determined that during testing, the fuel system for bank 1 was too lean. "

I replaced the O2 sensor, and plugs, but still the check engine light comes back on a few miles after being reset.

I also have the bucking/hesitancy problem accellerating, mostly in 1st and 2nd.

Parts shop guy says I'm looking at a fuel system issue, which makes some sense. The only other thing I'm thinking is the plug wires and ignition coils.

The printout from AutoZone says the probable causes are:

1: If the codes for both banks are given, suspect fuel pressure or mass air flow sensor.

2: Oxygen Sensor Defective

3: Ignition misfire-repair

4: Fuel injector problem.

Any advice is appreciated. I'll share what I learn as I try to figure it out.

 

[jdbru]

Figured it out, thanks to pro2002 in another thread.

I've got a cracked tube between the MAF and the throttle body.

Put some tape over it (for now) and the hesitation went away. Reset the check engine light and it hasn't come back on.