Running rich cause pinging

**rickssz** · 02-09-2008, 12:17 PM

Will removing cats make my car run rich? I read that but thought increasing exhaust leans things out. Well regardless cats are gone and Im hearing pinging under load that I didnt notice before. Could I be running rich and would that cause pinging?

**Firebirdjones** · 02-09-2008, 01:44 PM

Generally speaking, freeing up the exhaust will make the engine run leaner,,,and more fuel is necessary in most cases.

If your car is running on the lean side,,,,the computer will try to compensate by adding fuel and you will see + fuel trims.
It would be best to scan the car and see whats going on. It would have to be some serious knock for you to hear,,,,as the stock computer tune pulls a ton of timing when the knock sensors pick up the slightest knock before it's even audible,,,at least thats been my experience.

To answer your other question,,,yes running lean will cause detonation. Generally running richer will cool the cylinders with excess fuel and tend to quench a "MILD" detonation problem. Hope that helps.

**Tracker9118** · 02-09-2008, 01:54 PM

Originally Posted by rickssz

Will removing cats make my car run rich? I read that but thought increasing exhaust leans things out. Well regardless cats are gone and Im hearing pinging under load that I didnt notice before. Could I be running rich and would that cause pinging?

TRY A GOOD OCTANE BOOSTER LIKE NOS YOU MAY HAVE LOW OCTANE GAS.

**0rion** · 02-09-2008, 03:25 PM

my first question would be how do you know for sure it's pinging? When you yank the cats the exhaust note is gonna change. Did you go from manifolds to headers because that will cause a serious change in exhaust note. Could it not be ping but be just a difference in sound? I'm not saying you're not pinging but it would be best to log the car to see what it's doing and how much it's doing it.

**rickssz** · 02-09-2008, 04:49 PM

Still using the same tankfull as before ping but it does sound like 87 or low octane ping. Yes switched to headers. The pinging I am refering to is like you would get in an M6 if you gave it a lot of pedal in 4th or 5th at low rpm/speed. Like oops this gear is too high I better downshift except I am an A4.

**0rion** · 02-09-2008, 05:09 PM

I would log it. You'll get a completely different sound out of headers than you will the stock manifolds. It's hard to describe the noise but it could be mistaken as pinging. Either way, probably not a bad idea to log the car anyhow to make sure. I guess you could have some pinging going on there but my gut tells me you're probably just hearing the headers. Could also be an exhaust leak but my bet it's just the headers you're hearing.

**rickssz** · 02-09-2008, 07:04 PM

What would account for the feeling of sluggish pick up and low torque when I give it the gas at low rpm which is when I heard the possible pinging? None of the happens at high rpm.

**0rion** · 02-09-2008, 07:58 PM

well, maybe you are getting some knock or that could also be from not having a tune for the headers. The only way to know for sure is to log the car and see what it's doing.

**sic2001** · 03-05-2008, 09:07 PM

did you ever find out what this was?

**rickssz** · 03-06-2008, 11:19 AM

No its been in the body shop for weeks so the ping took a back seat. If/when I find anything out Ill post it.

**sic2001** · 03-07-2008, 09:32 AM

I found out what mine was yesterday, its a bad fuel pump. Pressure would go down 10 lbs when I punched the gas but I can slowly go all the way to the floor but as soon as I punch it it pings all to hell. Gonna put a new pump in when it gets here but the mechanic is 99% sure thats what it is.