How does freer flowing exhaust affect pcm?
Thread Starter
Instructor
Joined: Aug 2007
Posts: 141
Likes: 0
From: Western Suffolk, Long Island NY
How does freer flowing exhaust affect pcm?
Since I installed a new Y pipe, and reduced the three doggy cats to one, I think I hear a slight ping during accel. The ping gets detected/corrected by the PCM in in 1/2 sec or so. I don't remember hearing it before. (Maybe I just wasn't listening as hard before)
Does this exhaust change somehow affect the PCMs timing determination?
90-auto-l98-no major mods
thanks
Does this exhaust change somehow affect the PCMs timing determination?
90-auto-l98-no major mods
thanks
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Changes or mods made on a SD car(727/730) ecm can have effects on the blm (rich/lean). While timing and fueling tables are pre-set in the prom, after changes are made to motor set-up they usually will need to be re-tuned. MAF cars seem to be 'forgiving' when doing some mods.
Thread Starter
Instructor
Joined: Aug 2007
Posts: 141
Likes: 0
From: Western Suffolk, Long Island NY
Changes or mods made on a SD car(727/730) ecm can have effects on the blm (rich/lean). While timing and fueling tables are pre-set in the prom, after changes are made to motor set-up they usually will need to be re-tuned. MAF cars seem to be 'forgiving' when doing some mods.
I just noticed that someone had a similar problem caused by a new Bosch 02 sensor. I installed one along with the Y. I am going to switch back to my old 02 and see what happens.
