I just had my Tri-Y headers, 3 inch cat, and SLP cat-back installed. The shop that installed everything said that I need to replace the spark plug wire on the #3 cylinder because it was way too close to the header. I took it back a couple days later because I heard what sounded like a rattle snake listening from the inside of the car and I thought it might be an exhaust leak. He went over the entire thing and said there was no exhaust leak but that the #3 cylinder was firing just outside the exhaust port right inside the header tube and that replacing the plug wire should take car of it.

Today I replaced about 4 plug wires with new one's so that all of the wires would be 90 degree ends for header clearance. I then started the car and it didn't quite sound right so I had a friend stand behind my car while I launched at about 1/2 throttle. HE SAID HE HEARD POPPING JUST LIKE CAPS GOING OFF COMING OUT OF THE EXHAUST TIPS. We did this 3 times and each time he heard the exact same thing, he said it sounded like those little plastic caps filled with gun powder that you hit with a rock on the ground going off, only under throttle though.

We checked and double checked all of the spark plug wires and they are all in there perfectly, not a single one touching the header pipe.

Please help me!

 

Was it popping as you let off the gas or as you were building RPMs? Mine pops down after I let go of the gas as the RPMs go back down due to the free flow exhaust.

 

That's what I was thinking.

 

It's "during" acceleration.

 

sounds like a miss. check your coil to distributor wire too.

 

rather simple, double and triple check your firing order. Those plug wires are easy to get mixed up.

 

Firing order, that makes sense! I'll check it out right now using this diagram I found:


If that's not it, I'll be back

 

THAT WASN'T IT, so I'm back

All of the spark plug wires are exactly where they are suppossed to be. Now I did find that the #8 plug was not "snapped" on to the distributor cap but that wouldn't be my problem would it? It was firmly on there but it just wasn't "snapped" on.

Now what???? I also checked the coil to distributor wire too as also suggested and it checks out fine. Keep in mind these are brand new plug wires without even 500 miles on them. Help!

 

maybe you are running rich and you some fuel igniting do to heat in your new exhaust.

another quick question referring to exhaust popping ehen rpm's are dropping. I have an 88 monte carlo ss w/ a 48o lift cam and an edelbrock performer manifold w/ dynomax headers ot a catless true dual x pipe exhaust w/ flowmaster 40 series mufflers...what causes that "popping sound" b/c it is extremely loud in that car.

 

id say it is just detonation in the exhaust pipe. unburned fuel from the cylider is firing in the exhaust do to the heat. or just backfiring out the exhaust. timing can cause the valves to stay open sometimes. just to double check look at the timing again if thats not it then i would say u have nothin to worry bout. i dont and my exhaust pops like that.

 

yeh thats what i figured, thanx alot

 

sounds like backfire to me... check the timing. mine did the same thing. also, scan it for codes. maybe the knock sensor's gone or something. u get a ses light?

 

I'll check the timing....