gambler669

Let me start by saying my car runs great. even when the check engine light comes on, it still runs great, doesn't seem to go into a limp mode. When I got it smogged, it was running super clean, but it failed the evap pressure test. I found the bad lines and replaced them, but then I all of a sudden got a check engine light before I could go back and retest.


I was getting these errors before, but they never set the check engine solid. Now I'm getting the check engine light that sets itself after a short drive and it stays until I clear the codes. My OBD reader is giving the following errors:

41,42, electronic spark timing. I've checked the wiring and it is solid and replaced the distributor module, but no change. The spark plug wires are pretty new and 8mm resistor. It seems to change from 41, to 42 depending on when I scan. Even when the check engine comes on, it appears the timing is still at the ECM because when I shoot the timing, it is advanced and not like when I unplug the timing set wire. Any ideas on what else to check?

25, 32, MAT too high, EGR fail. I replaced the EGR as it was sticking and old. But it didn't change the codes. I physically verified with my vacuum pump that the valve is opening as it stumbles at idle when I apply vacuum. I then connected it to the vacuum port and verified the solenoid it turning off and on as I open and close the throttle. I checked the resistance on the EGR switch that is on the tube and it is 665 ohms hot and 1010 when cold, so I cut the wire and checked the switch and it appears open (engine hot). Anyone know what readings I should be seeing off this thing and how fast it switches?

33, 34, MAF flow high, MAF flow low. I've cleaned the MAF. I've cleaned the throttle body, but it seems to throw the 33 at low rpm and the 34 at higher rpms...the codes are constant, but intermittent. I changed the two relays, and made sure the wiring was not grounding. I get the 12v on the purple wire and the approx 4.5 v on the green wire at the MAF.
Could it be related to the EGR issues?

Could all these issues be intermingled? Could it be the ECM?