I jut swapped my 93 octane tune for an 87 octane with 80%TM removed and got the cats removed. Now heres the deal. With the 93 tune, the engine had a bad ping under slight load or sometimes no load at all. I thought maybe it was too much timing. Now with the 87 tune, its worse. The engine has a BAD ping from anywhere from just above idle to WOT.. What in the hell is causing this??? I know it can't be good for the engine.
Removing cats may have something to do with it. Did you descreen the MAF sensor or anything like that? Anything that makes the engine breath better leans out the engine and can cause pinging. Maybe you just got a crappy batch of gas? If it's old it could have lost a lot of its octane.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
It does it no matter where I buy gas from, so I wouldn't think it was bad gas. I guess I could change the fuel filter to make sure its not blocking fuel flow. I did descreen the MAF, but told Allen that, I can't put the screen back in, i kina messed it up. I had Allen turn the rear o2 sensors off, and I told him I was removing the cats, so would he have compensated for this, or is it still running lean?? I don't know if it will hurt anything or not, but it sounds horrible.
Get you a new MAF or borrow one and see if that fixes your problem. Descreening the MAF is a real no-no. You have to get your PCM adjusted using the hands-on approach to compensate for the air flow being screwed up over the MAF once you descreen it. Whomever started doing that was nuts and has caused many headaches to owners that thought they could improve their performance by descreening the MAF. I descreened my old engine's MAF and it ran lean as a MOFO. I put a stock one back in and no more problems.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
So if I can salvage the screen, it might help? The screen is not beyond repair. I think that will be a project for this afternoon. Anything to get rid of that sound. Kinda sounds like a mini Duramax
Its sure worth a try.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Would a tune up help any? This engine has close to 100K on it now and still has factory plugs/wires and such. I've always been one for preventative maintenance, but I didnt know how long to wait with this engine, or the best plugs/wires for it either. This is my first Vortec.
Yeah try the tuneup and see if you cant repair that screen, maybe change the fuel filter while you are at it. Then reset the tune and have at it and see how it works out.
Chris
2009 Silverado, HPTuners, all stock.
I've had a minor pinging issue with my truck, but it was much worse before I got my tune. Talk to Allen, and I'm sure you and he can come up with the solution.
2002 ECSB, Nelson Tune, LS1 electric fans, 145A alternator, K&N FIPK, 160º T-stat, TB coolant bypass, Corvette servo, 4 headlight mod, blue LED gauge cluster
Got the screen put back in yesterday. I did it while watching McGyver (gave me some ideas about using an icepick). I'll get a fuel filter this afternoon and slap it in. Now, how do I reset the tune?? Its not the old gas pedal tothe floor 3 times deal is it??
Posting Permissions
Reply With Quote
