Ok, so i have a 2000 Monte Carlo, and the check engine light came on about a month ago. I had it tested and 3 codes came up. One was for the tire monitoring system sensor, one for the evap system (which i was having problems with at that time), and the other was for misfire on one of the cylinders. Well i fixed the third because my car was running like crap, and that code went away, but i didnt bother with the other two, since i had time before i needed to get my emissions testing. Well i took it up to the auto store just to have it tested again and now there are 5 codes coming up instead of just 2 like i thought there would be. The codes are C-1245, P-0341, P-0440 (the evap one), P-0449, and P-1404 (EGR valve). Does anyone know why so many more codes would come up now? Are any of the codes related, so one problem might be making another code come up? I just replaced the EGR valve about 3 years ago so i am surprised that it is showing up again. I did take the EGR valve off and and checked for carbon bulid-up, so could that have caused the code to come up? Any help i can get i would really appreciate, since i just dont want to start spending money just replacing things.

 

Also i should add that i had an issue to where i couldnt put gas in my car because of back pressure caused by Evap problem. I know one of the codes above is for that problem, does anyone know which one and what i need to do to fix it? From what i have read i think its the purge solenoid or something like that.

 

I know the C1245 is related to your abs. And if memory serves it's is the drivers side rear bearing.
Could be a bad ABS sensor or your EBCM isn't operating normally, check for a bad wire to your rear bearing/hub.
Check plugs and lines at EBCM as well.

If you just had your EGR valve out for cleaning I would suspect that's your culprit for that code

P0440- could be something as simple as buying a new gas cap
Or replacing carbon canister
Or like you said your purge solenoid may be on its way out.
I found with this code the easiest route is process of elimination as most of these parts are fairly inexpensive.
P0449 is also related to this code
Fixing one may fix both

P0341 I believe is your crank or cam sensor so that's were is start wit that