LTFT's high suddenly???
#1
LTFT's high suddenly???
My LTFT's have been around -1.6% at idle for years now. I did a log trying to resolve another issue and noticed that they are at 10% on one bank and 15% on the other at idle. I have checked and eliminated the following:
spark plugs
plug wires
connections
vacuum leaks
maf sensor
I am replacing the o2 sensors as they have 114,000 miles on them. I do not get any codes and the tune is fine other than idle. I get a high count in the misfire index as soon as I step on the gas but it goes away instantly and then the LTFT's go to -1% normal driving.
What else can I check??
spark plugs
plug wires
connections
vacuum leaks
maf sensor
I am replacing the o2 sensors as they have 114,000 miles on them. I do not get any codes and the tune is fine other than idle. I get a high count in the misfire index as soon as I step on the gas but it goes away instantly and then the LTFT's go to -1% normal driving.
What else can I check??
#3
#4
Check for a cracked exhaust manifold. That's was what happened to mine. The right manifold was cracked behind the shield, and my fuel trim was high like yours.
Replaced the manifold and all was good again.
Replaced the manifold and all was good again.
#5
Sure hope its not that, I just replaced it a few months ago!! Ill check that thanks!
Trending Topics
#8
Weird thing is yesterday everything cleared up and the LTFT's went back to 0%. Then today they are back to +15%.
I replaced ALL of the vacuum lines. Checked the manifold, exhaust and intake for leaks. I checked fuel pressure, replaced the fuel filter and ran seafoam through the fuel system.
I replaced the EGR gasket and cleaned the valve as well. How do I test to see if the EGR and MAF are functioniong as they should?
#10