pyroone

ok...theres something wacky going on here, and I cant seem to get this straight. According to a mechanic friend of mine, Im missing on a cyliner, its not bad, but you can hear it if you listen closely. He thinks its a fuel injector. I ran the enngine codes and I got 3: system too lean; bank 2, O2 sensor circuit slow response; bank 2, and lack of HO2S1 switches-lean; bank 2, sensor 1. Talked to the guys at AM and they said it sounds like a fuel injector out on the left side of the engine (bank 2) and that i shouyld try unhooking one coil wire at a time. The one cylinder that showed no difference was the culprit. However, when I did this, all cylinders got worse...meaning that they where all fine!! Now my engine doesnt run bad, I think its gotten a little worse over the years, but i figured it was normal...but I have noticed by MPG has gone down the drain...bad. Could it be a simple fix like a fuel filter thats WAY over due for changing? Or is this something else?

tdpower

I'm not a mechanic but here is what I would do:

Replace spark plug/wires
Probably have a bad o2 sensor
Run some fuel treatment on next couple of tanks

pyroone

fuel treatment as in like a fuel stabilizer, or like an injector cleaner? I founf out last night that the store i fill up at has water in there gas, another mustang friend of mine started having serious issues with hers, she put in a bottle of sea foam and filled up at conoco and hasnt had any problems since.

Boost Logic

Well if you think its a bad injector, pull it out and move it to the next cylinder.
See what you get.

ayrton02

Sounds like you need a full tune up. I haven't ever heard of the injectors going "bad" on our cars. Run some SeaFoam through the gas tank, vacuum line, and crankcase, then change the oil 100 miles later. I would start at the plug wires/plugs. Then fuel filter. If that doesn't solve it, then check the ignition coil. If you do change the O2 sensor, do it after you SeaFoam.

I had a bad plug wire and mine missed. Simple fix.