Can Fuel System Cleaners Cause a CEL?
Thread Starter
Melting Slicks
Joined: May 2018
Posts: 2,091
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From: Question Government
Can Fuel System Cleaners Cause a CEL?
Is it possible for a fuel system cleaner, added to the gas tank, can cause a CEL with a "Fuel Mixture Lean" code? Or would my CEL coming on just be a coincidence after doing so?
Last edited by RetroGuy; Sep 30, 2021 at 09:54 AM.
Drifting
Joined: Apr 2016
Posts: 1,286
Likes: 611
From: DFW Texas
Unless you filled up with cleaner and then added a can of gas, I would say no & just a coincidence. Was the code generic or did it specify the bank that is reporting the lean condition. Usually associated with a vacuum leak. Check to be sure you have a tight seal on your intake system in front of the MAF sensor. Have you recently performed any maintenance or work under the hood, changed your air filter, as that would be suspect. You may just go over everything you touched to ensure there were no air leaks introduced.
GD
GD
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
Doubtful something like Techron would cause a lean code…do you have a P0171 AND a P0174 ??…if it’s just one bank and the other banks fuel trims are normal it something “bank specific”…intake runner or maybe an bad O2 sensor…if both DTC’s now you have to look at an intake leak, fuel delivery or a MAF issue…you can have it where you have a P0171 and the other bank fuel trims are just short of setting a lean code for the other bank…best to use a scan tool to accurately diagnose this !!…with a scan tool fuel trims will decrease as you increase the RPM with a vacuum leak…easy to diagnose !!
