Just had my LTs, y-pipe, and catback installed

**98TransAmWs-6** · 08-27-2010, 01:02 PM

I just had my LTs, y-pipe and catback isntalled but my mechanic said that I have a misfire in cylinder 6 after the install but I didn't have it before hand, would this just require a tune to fix or is there some other reason for it?

Any information would be helpful. Thanks.

**02fbody35th** · 08-27-2010, 01:20 PM

did you replace the plugs and or wires when you did the install. make sure the wires arent touching the header and melting. also make sure that they are properly plugged onto the spark plug and coil

**razer900** · 08-27-2010, 01:21 PM

cracked plug from install, i think i had the same plug broken on my swap too! lol, change the plug and enjoy!!

**98TransAmWs-6** · 08-27-2010, 01:24 PM

No I did not replace them but one cause i broke that plug by accident. Should I just replace them all? I just don't want to end up replacing them and it ends up being something else.

**razer900** · 08-27-2010, 01:44 PM

i think most change them all out when doin headers but you can probably get by with changin #6. Scan again and hope the misfire is gone

**Too Fast** · 08-27-2010, 01:50 PM

99% chance it is a plug/wire connection issue, if you had no problems before the headers.

**jeffsWS-6** · 08-27-2010, 02:20 PM

for NGK TR55 plugs and MSD wires brand new for $75, whats 75 when you probably spend $1000.

**35th-ANV-SS** · 08-27-2010, 02:33 PM

Agreed with everyone else here. During LT installs, most shops change the plugs. Check that plug out.

**rajiv1998** · 08-27-2010, 02:41 PM

99.99999999999% its the plug. I had the same problem when I did mine. The MSD wire's got to close to the heat sheilds and it started to melt. (Actually I was a dumbass for not keeping the stock metal boots from the stock wires). Install went fine and a few days later it started to missfire and the SES light came on. Did a scan and it came up as "Cylinder 6 missfire". Pulled the plugs and the #6 plug was melted beyond recognition.

**98TransAmWs-6** · 08-27-2010, 03:53 PM

Alright thanks for the info I'll check that plug out. Also I'll post some pics up at soon and maybe a video.

**Too Fast** · 08-28-2010, 02:13 AM

Originally Posted by rajiv1998

99.99999999999% its the plug. I had the same problem when I did mine. The MSD wire's got to close to the heat sheilds and it started to melt. (Actually I was a dumbass for not keeping the stock metal boots from the stock wires). Install went fine and a few days later it started to missfire and the SES light came on. Did a scan and it came up as "Cylinder 6 missfire". Pulled the plugs and the #6 plug was melted beyond recognition.

Had to top my 99% prediction, eh?

**pajeff02** · 08-28-2010, 03:45 AM

Might try simply re-seating the plug wire. Apply pressure until you hear one "click" at the plug and two "clicks" at the coil.

**98TransAmWs-6** · 08-28-2010, 11:06 AM

I checked my plug and wire and they both look fine. Would it being gapped wrong cause this issue? Just to check do you guys know what the correct gap is?

**marksls1ta** · 08-28-2010, 11:13 AM

start car in a dark place and look for spark jumping.

Mark

**rajiv1998** · 08-28-2010, 04:08 PM

Originally Posted by Too Fast

Had to top my 99% prediction, eh?

I just HAD to

**98TransAmWs-6** · 08-28-2010, 04:57 PM

Another question, since I have a miss in cylinder 6, would my rough idle be related to that? I am pretty sure I already know the answer just wanting some comformation on it though.

**razer900** · 08-28-2010, 04:59 PM

Originally Posted by 98TransAmWs-6

I checked my plug and wire and they both look fine. Would it being gapped wrong cause this issue? Just to check do you guys know what the correct gap is?

any results yet? altho the plug may look allright, change it out and see what happens, if problem persists then swap plug wires with another cyl and see if the problem follows the wire

**rajiv1998** · 08-28-2010, 05:05 PM

Originally Posted by 98TransAmWs-6

Another question, since I have a miss in cylinder 6, would my rough idle be related to that? I am pretty sure I already know the answer just wanting some comformation on it though.

Yes, it certainly can and most likley will. When my plug wire burned, the idle was really bad. It kept on surging and popping. The car would never idle properly and you could clearly hear it missfire in the exhaust. It never rolled outta 1'st without popping and jurking, kind of like if you release the clutch to quickley.

**razer900** · 08-28-2010, 05:12 PM

Originally Posted by rajiv1998

Yes, it certainly can and most likley will. When my plug wire burned, the idle was really bad. It kept on surging and popping. The car would never idle properly and you could clearly hear it missfire in the exhaust. It never rolled outta 1'st without popping and jurking, kind of like if you release the clutch to quickley.

mine was a bit different, it idled fine and ran fine till i got on it, then it backfired like a machine gun. Every situation is different tho. Op, your car might need a tune after the header install also, could be runnin a little rich now. get the misfire figured out first then go from there.

**rajiv1998** · 08-28-2010, 05:26 PM

Originally Posted by razer900

mine was a bit different, it idled fine and ran fine till i got on it, then it backfired like a machine gun. Every situation is different tho. Op, your car might need a tune after the header install also, could be runnin a little rich now. get the misfire figured out first then go from there.

Mine never ran good at WOT either. I doubt the missfire is due to the tune. Headers shouldnt change the A/F ratio, timing, spark etc... too much. People go months without tuning after LT install. This sounds like an internal problem. Pull out all your wires/plugs and make sure they are ok. Recheck all your ignition connections. Try to run a scan if you can. Go to 2 or 3 places and get it looked at (most are free) to make sure they are all pointing to the same thing.