Trying to figure out why it feels like i'm getting random misfires without any codes coming up. My other cobalt did the same thing. Here's some random info from a fancy scanner tool I was able to use.

Note: GMS1 with catless DP with no 2nd 02 sensor, zzp intake tube, K&N typhoon filer, injen upper ic pipe, Is does have an hp tune to turn off cat warmup and disable p0420 and the 2nd o2 sensor. I have looked at the lambda on the scanner during a pull #yolo and it's from .95 to .87 which I think is GMS1 parameters. I didn't use hptuners on it, it came like this.

Incomming pics. I'll just link you guys to the imgur page. http://imgur.com/a/1Tzkx#0

 

How are those intake valves looking?

 

Is it like jerking a little while u drive on and off, and more so if u are against a strong wind? If so, change ur maf sensor. Had that issue. New maf solved it

 

I don't know... I'll see if I can get the intake mani taken off this weekend and get it looked at.

 

le bump, would like some super scientist tuner help.

 

Clean your valves

 

Cylinders 2, 3, and 4 are doing some funky business there, particularly 2/3. It's tough to see exactly what's going on and why without more data though. Either way, you're likely seeing heavy injector misfire for one reason or another.

 

How's your fuel? Also that seems like a fair bit of mods for no tune. Could very well be the intake.

 

Looks like gms1 fueling to me if thats what you're reading for lambda. Thinking you need a touch up on your tune if you're running a decent amount of boost with those lambda targets too.

 

Took off the brake booster line to the intake mani and the little pvc thing and look a wire and stuck it in there, jesus christ did that wire get dirty, had to clean it many times. I do need to walnut blast it, clean the combustion chamber, new spark plugs, clean the tb. Lots of maintenance