LTFT High Exhausted all efforts
Thread Starter
Teching In
Joined: Jul 2016
Posts: 1
Likes: 0
LTFT High Exhausted all efforts Hello all,
first off this is an LS swap that has been running perfectly for 20K+ miles. Threw a code for knock sensor circuit fault so I pulled the intake and replaced the circuit. Code gone. Then once I had everything all button up after the repair, I started getting an actual knock code and LTFT and STFT in bank 2 was excessively high and Bank 1 was also high but not nearly as high as bank 2. I have HP tuners and have exhausted all my efforts.
Fuel Injectors tested and work(only tested for function.)
All fuel circuits work.
Swapped ECM
Swapped MAF, MAP, idle air sensors
New O2 Sensors
Fuel pressure good
Spark plugs and wires good
Whenever I run it for a couple seconds Cylinders 1,2 and 4 exhaust pipes are not nearly as hot as the others.
If I changed to closed loop and disconnect MAF B1 goes negative and bank 2 is positive but is 20% LESS than if MAF is plugged in and not in closed loop.
ANY ideas or things to check would be much appreciated.....
first off this is an LS swap that has been running perfectly for 20K+ miles. Threw a code for knock sensor circuit fault so I pulled the intake and replaced the circuit. Code gone. Then once I had everything all button up after the repair, I started getting an actual knock code and LTFT and STFT in bank 2 was excessively high and Bank 1 was also high but not nearly as high as bank 2. I have HP tuners and have exhausted all my efforts.
Fuel Injectors tested and work(only tested for function.)
All fuel circuits work.
Swapped ECM
Swapped MAF, MAP, idle air sensors
New O2 Sensors
Fuel pressure good
Spark plugs and wires good
Whenever I run it for a couple seconds Cylinders 1,2 and 4 exhaust pipes are not nearly as hot as the others.
If I changed to closed loop and disconnect MAF B1 goes negative and bank 2 is positive but is 20% LESS than if MAF is plugged in and not in closed loop.
ANY ideas or things to check would be much appreciated.....
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
Years ago I buttoned up my car after doing something under the hood, drove about a mile, pulled into a parking lot because it just wasn't running quite right... popped the hood, heard what sounded like a trashed bearing, my heart sunk.... and then I spotted a disconnected PCV hose. The hissing sound was air getting sucked in. Plugged it in, the noise went away, and the engine ran right again.
