I have a 2009 ss tc missfire at high rpm after installing an intake I replaced my plugs and coil packs still reads missfire on 1 2 3 cylinder but if I drive it at half throttle it works fine should I just put stock intake back on ?

 

Mine did the same after my intake swap. Once I got it tuned, the fuel output got adjusted, no more popping from the exhaust.

Not sure if it's the identical issue, but from what I've read, swapped intakes on the lnf are wonky until tuned.

 

Yes mine back fires like crazy I'm just going to put stock back on see if it works fine, but I can't get it to stop missing at high boost atm

 

When I bought my 09LNF i installed a Hahn/k&n intake and it ran great for the past 4 years no misfires. I then got hahns charge air piping, installed the upper pipe and said **** the throttle body one for almost 2 years and it still ran great lol. About a month ago I finally installed the throttle body pipe and just today I had a random misfire P0300. Don't know if it's related to the pipe swap but it didn't make sense because I drove the car to work, it was fine then finished work and turned over an engine light came on...

 

Mine thru same code but will missfire on different cylinders each time I dropped it off at a gm tech tonight see what's going on 4 new spark plugs and coil packs and put my stock pipe back on and it still misses only at boost from 12 pounds to 18 Pounds

 

Noooooooo. Never go to the dealership unless it's a recall or warranty fix. They will rob you and say have a nice day

 

It's not a dealer local gm tuner shop I gave up on dealer prices

 

It's not only the price. They cut corners. But good to hear

 

Have you ever cleaned your valves?

 

No that's a job I've been putting off lately, seems like a pain in the ass.

 

I got it fixed was coil packs they kept breaking even new ones I'd put it on dyno had to re tune my car with intake 278whp guy told me if you do anything to these cars it has to be replaced or modded parts tune it and you won't have a issue

 

What has to be replaced?

 

Yup just got my parts in and tune done and the 4th coil pack was fucked. Put a used one in that my tuner had and it's fine again. I'm hoping I don't have to replace the other 3.