Miss at low RPM and heavy load...solved!

[tktrain]

Hey guys! I have good news. I finally seem to have put to rest a problem that has been dogging me for years...literally! The low to moderate RPM and high load miss I have been experiencing for the longest time seems to be gone. I installed a new Bank 1 Sensor 1 O2 sensor and a new fuel filter on Saturday. I disconnected the battery for a few minutes afterward and then went on an extended test drive and the problem appears to be gone. Hallelujah! The truck pulls very smoothly now, even at low RPM. It seems like even the occasional bucking I used to see at about 1300 to 1400 RPM cruising in OD is gone.

I have driven it about 100 miles now and no sign of the problem. The only question is did the O2 sensor fix it or was it the fuel filter. I wish I had done them one at a time, but it was just too easy to get them both done while I was under the truck. When I drained the fuel filter later there was a positively murky brown tint to the fuel coming out from the inlet side, so I have to vote for it being the culprit. But the smoothness at low RPM makes me think the O2 sensor may be responsible. By the way, I am at 120K miles and I had no codes or pending codes showing. I had replaced the Bank 2 Sensor 1 at about 100K miles when I got a code showing it had gone down.

 

[stup]

120k miles, had you ever replaced the fuel filter before? if not, it could have been your problem. I doubt it was the o2 sensor, as it plays no roll in engine performance, only emissions monitoring.