Hello all,

The car seemed fine until just recently... I left the gym in the morning, opened it up merging onto the freeway and as I got on it it seemed to still have power but also like a fluttering when I got on it... Under moderate load it seems perfectly normal. No check engine light, but my reader pulls a p0300...

Thought it was the Injen cold air intake, as the rubber coupler between the manifold and the pipe didn't seem to fit perfectly, fixed that issue but still no good...

I feel like I have to change my precats although I haven't seen that check engine light code since summer... not sure if that can be related...

 

It's most likely a weak coilpack as it's failing under load but ok when just cruising or light throttle. Unfortunately you got the lame generic 0300 code which tells you nothing except you have a misfire somewhere. Clear it and hope that 0301-0306 comes back next time indicating the troubled cylinder.

In the meantime, you can perform a power balance test. With the engine running, disconnect one coilpack plug at a time and listen for a change in the rpm. If you don't hear a change, you've probably found the bad coilpack. If you do hear a change in the rpm, this is a good sign and an indication of a properly functioning coilpack. Plug it back in and move on to the next cylinder.

 

I'll try that