I just picked my car up from a shop about 10 min ago and on the way home the car starts back firing, not boosting, sounds almost like a machine gun for the exhaust. I am not real sure what is causing this, but if you have any input I would appreciate it.

 

Lets start with, what shop? What did you have done to it?

 

how about.... what kind of shop did you go to... what did you have done to the car ? if its a tune up shop, start from there, if you went to a detailing shop there are other concerns.... sounds like a leak somewhere for the boost issues, or something loost on your exhaust manifold

 

im thinking your IC pipe may have fallen off, check all your IC pipes to see if they came off. If one did, it will run terribly if it runs at all and you would obviously have no boost.

 

Sounds like maybe an intercooler hose is loose.

 

It was at a tuner shop, and they installed a clutch into my car. Okay the weird thing is that the car will run fine below 2k rpms, and it will run okay above 4k rpms. It has a horrible loss in power between the two.

 

sounds like an ic piping came loose

 

I'm thinking ic piping too, but when I first put my mbc on, I reversed the lines. Car sounded similar to your situation. They wouldn't have messed with that if you have one anyways though.

List of mods and work done might help.

 

Mods

K&N intake
Polished intake pipe
Turbo smart MBC
Turbo XS Utec
LS 3" downpipe
Megan Race Cat
Megan Racing Cat-back
Walbro 255
Greddy type RS

Work done = clutch install

 

Where is your mbc installed? check the lines to make sure they are secure. What does your boost gauge say?


Ditto on all ic hoses, especially lower connections.

Ditto on exhaust connections, could be an exhaust leak, but that may be even more remote poss. than mbc hoses.

 

I will just jack the car up in the garage and start going through all the above mentioned problems. I guess I am in for a night of trouble shooting lol. Oh well I guess that what happens when you drive these cars. Thanks for the help all.

 

It sounds like you are misfiring at peak torque. It could be as simple as fouled plugs. When my plugs go bad, or if I have the wrong heat range, I misfire badly right where the boost spikes, which is in the 3500-3700rpm range, depending on the gear being used.

 

make sure your MAF is plugged in.

 

When I had my clutch replaced the shop bent my lower I/C pipe. There was a leak at the flange where it meets the turbo.

 

Whats the sparkplug gap on the evos? I can't remember them off the top of my head.