Error Codes P0172 and P0300
This is my first post here. I tried looking for posts with similar issues but could not find quite what I was looking for.
2010 GMC Terrain, 2.4L, Front Wheel Drive
My check engine light just came on. We took it to AutoZone to get the error codes checked. They came back with a printout explaining that the two error codes they read were: P0172 "System Too Rich (Bank 1)" and P0300 "Random Misfire Detected". It also stated that the most likely issue is my Timing Chain.
After a few calls to nearby mechanics I've been told that it may be my timing chain, and it'd be (cheapest quote I have recieved) $3500 for a fix. They also have stated it could be several other issues.
Currently the vehicle is running well. I do not hear any slapping or rattling while running or idling. A couple times in the last week it did run and die about 3 seconds after turning off the ignition switch. I think it sounds like there is a leak in the exhaust. Aside from that, no issues.
If anyone has advice on how I can troubleshoot to verify Timing Chain vs other issues, I would greatly appreciate it.