Fuel Trim Codes and Random Misfire
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Teching In
Joined: Dec 2019
Posts: 37
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From: Md
Fuel Trim Codes and Random Misfire I've been chasing this issue for so long and need some help
Turbo 4.8, Been dealing with this and transmission issues for a couple years now. Finally rebuilt the trans and the truck ran as good as it ever has and the fueling issues seem to have disappeared but of course they came back.
It misses noticeably at low load/low rpm usually around 2500rpm in 3rd or 4th gear. Getting P1174 and 1175(Fuel Trim out of balance) and usually accompanied by p0300.
The one time I did get p0301 and seemed to lose cylinder 1 altogether but that has not happened since
Of course my good scanner broke so I am limited on diagnostics but I replaced the plugs and the issue seemed to go away for a little but came back of course so this may be a clue.
Fuel Filter is good(10 micron)
Replaced O2's
No visible vacuum hose issues
Plugs look ok but have a good bit of oil on the threads(would having gapped rings cause this)?
What else should I be looking at? Could it be as simple as a tuning issue?
Working on getting a gauge setup to monitor fuel pressure
Thank you
Turbo 4.8, Been dealing with this and transmission issues for a couple years now. Finally rebuilt the trans and the truck ran as good as it ever has and the fueling issues seem to have disappeared but of course they came back.
It misses noticeably at low load/low rpm usually around 2500rpm in 3rd or 4th gear. Getting P1174 and 1175(Fuel Trim out of balance) and usually accompanied by p0300.
The one time I did get p0301 and seemed to lose cylinder 1 altogether but that has not happened since
Of course my good scanner broke so I am limited on diagnostics but I replaced the plugs and the issue seemed to go away for a little but came back of course so this may be a clue.
Fuel Filter is good(10 micron)
Replaced O2's
No visible vacuum hose issues
Plugs look ok but have a good bit of oil on the threads(would having gapped rings cause this)?
What else should I be looking at? Could it be as simple as a tuning issue?
Working on getting a gauge setup to monitor fuel pressure
Thank you
