Tolley's94z28

iTrader: (4)

ok so i just installed off road headers and y-pipe, as well as an egr delete. then i sent the pcm to madtuner to be tuned, becuase it was back firing and i heard that deleting the egr will do that. well i got it back today and it is still back firing, what could be wrong with it?

its a 93 lt1 btw

96ssindeed

How bad is it backfiring? Mine makes some pops and small backfires every now and then. I attribute it to simply not having cats.

djjab57

iTrader: (17)

Probably burnt a wire or two, check the second wire on passenger side

Tolley's94z28

iTrader: (4)

its a frequent backfire, it seems to be regular/constant

Tolley's94z28

iTrader: (4)

it may just be time for me to change my plugs and wires

old93camaro

iTrader: (8)

have you data-logged it yet may have a exhaust leak from somewhere or like some one said bad plugs and wires

94maro

check your spark pluggs see if u cracked one or so..alos check your wires might have burned one..make sure your o2 sensionrs r properly working also..if non of that your opti might be on its way to the trash..

Tolley's94z28

iTrader: (4)

ok so it mostly does it at idle, or in drive, and it feels like its running pretty rough, so im thinkin maybe i have a miss, so its probably a plug or wire right?

joelster

Most likely a wire. If the headers are pacesetter headers look to cylinder number 5. The 3rd one back on the driver side. The boot will be very close to the pipe. You have to pull the wires off and closely inspect them, you can't just peek under the hood. Sometimes a small crack in a wire will be very hard to see unless you bend the wire. Any crack will allow the spark to jump and that cylinder not to fire.

94maro

and if its not the wire take the spark pluggs out and make sure the white part has no cracks or that also will make a misfire...

96ssindeed

you may have also crossed a wire if you unplugged them to put the headers on. But yea it sounds like a plug/wire issue

Johnny-LT1-runner

iTrader: (15)

Wires and O2's, check em.

00FlowCamaro

If you need to redo the wires, which it seems like you do, get the Over The Valve Cover Wires. You won't regret it.

moderate Z28

X2 I couldnt live without em anymore. One of the very best things you can do to these cars.

93TAJ.C.

iTrader: (1)

I hate the look of otvc wires, it just looks redneck. I did mine as close to stock as i could. and it worked perfectly, i did have my engine out and did it with the headers off, then pulled the wires off the plugs, put the headers on, and popped them back on the plugs. also, make sure you have all the plug wires going to the right plugs, its a very common mistake to cross them up.