Backfiring between shifts
Thread Starter
Race Director
Joined: Mar 2004
Posts: 12,466
Likes: 886
From: Fort Wayne IN
2025 C5 of the Year Finalist - Modified
C5 of Year Finalist (performance mods) 2019
2017 C5 of the Year Finalist
2016 C5 of the Year Finalist
2015 C5 of the Year Finalist
Backfiring between shifts
Car is bolt on, dyno tuned, no cats. Seems that most of the time when I got to shift (M6) I get a backfire. Rear O2's were deleted, everything else was in sync when we did the dyno tune in Sept. Noticed it pretty much standard after that.
Still a semi-newb to the LS1 world, wondering if this is a normal nuance (such as the popping on decel that's so common on the LT1's), or if it's cause for concern. TIA
Still a semi-newb to the LS1 world, wondering if this is a normal nuance (such as the popping on decel that's so common on the LT1's), or if it's cause for concern. TIA
Racer
Joined: Apr 2005
Posts: 348
Likes: 2
From: Miami Fl
mine still has the factory tune except for the fan temp turned down and it backfires between shifts also,i have the 2 rear cats and b&b bullets,i think it might be due to the h pipe and the x pipe might fix it but i'm not sure,i'll let you know after i do the exhaust in a few days,also does yours backfire when you accelerate to like 3k and let off then lightly get on the gas again?
Thread Starter
Race Director
Joined: Mar 2004
Posts: 12,466
Likes: 886
From: Fort Wayne IN
2025 C5 of the Year Finalist - Modified
C5 of Year Finalist (performance mods) 2019
2017 C5 of the Year Finalist
2016 C5 of the Year Finalist
2015 C5 of the Year Finalist
Sounds like it's a common thing. I've got a full exhaust (LG Pro's, no cats, Corsa Indy's), no leaks that I can find. I'll just live with it, or shift faster. 
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Drifting
Joined: Apr 2004
Posts: 1,530
Likes: 250
From: CT
It may be that the decel a/f cell is set a little richer than it needs to be. I had a new tune a couple weeks ago by Slowhawk (Dez Racing) after leaning out the decel cell, most of the popping at shifting and decel is now gone (kinda miss it though). My cold start a/f was so rich that I was getting popping during cold idle, before the pcm would go into closed loop mode.
From what I've seen it's a common LSX trait however and nothing to be concerned about.
Just my .02. Hope this helps a little.
From what I've seen it's a common LSX trait however and nothing to be concerned about.
Just my .02. Hope this helps a little.
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
Originally Posted by HRDTOPC54FUN
My cold start a/f was so rich that I was getting popping during cold idle, before the pcm would go into closed loop mode.
