Hi everyone,

Need troubleshooting and repair ideas for my 2009 Matrix 2.4l and a P0302
Here's the info.

Yesterday- the check engine warning light flashed for about 30 seconds at 70mph.

Was able to drive 30 miles home and check engine light did not return.

Pulled out the scan tool and found P0302 code = cylinder 2 misfires.

Today - the "Maintenance Needed" Light flashes at start up but the check engine light has not returned

Also noticed on the scan tool the STFT was 7.0 and LTFT was 3.9 (fuel trims)

Idle speed is about 800 RPMs - feels OK

My first idea to attack the P0302 code is to:

• swap coil packs between cylinders 2 and 4, erase the codes and see if the misfire moves to 4 on a rescan.
• If the code moves to 4, then I know I have a bad coil.
• Replace all 4 plugs and the bad coil or maybe all 4 if I can get a deal on Denso coils for the Matrix.
• Do a complete fuel system cleaner (Techron maybe - since ATS is out of stock)

Am I missing steps in diagnosing and solving the P0302 issue?

Any ideas on the STFT / LTFT numbers and why these might be so HIGH? What I could do to bring them down?

Could this ST/LT fuel trim issue be because of the P0302 issue?

I really appreciate any advice.  

Bill