This is in regard to a 2002 Daewoo Lanos.
If I use a generic OBDII scan tool to clear the codes, the codes clear, but a new code immediately sets: P1618, and then the engine will misfire a lot, the check engine light will blink while driving, and the transmission won’t shift out of 1st gear.
If I disconnect the battery to reset the computer, the engine runs ok other than a minor miss at idle, and the transmission shifts ok, however the check engine light will only stay off for a short time, maybe 40 miles. Once the evaporative emissions monitor runs, it sets the codes P0442 and P0456. I had two shops which specialize in emissions repair do a smoke test and perform additional tests to find the source of the alleged leak, and neither could find anything. One said the PCM might be defective, the other said without a factory scan tool, they cannot diagnose this further. No one has this special tool.
The problem for me is that this car could really use new front struts, because when I back out of my driveway, unless I go super-slow, it “bottoms out” and the towing hooks hit the road surface. However I cannot justify paying to have that done if I’m not going to be able to get this thing through emissions this summer.
I think the PCM really is defective, however I am concerned that if I get a used one from a junkyard, that will not be acceptable for emissions testing purposes because it will then read the VIN from the junked car.
On the other hand, if I can get all of the monitors to run EXCEPT for the evaporative emissions, then I can pass emissions and renew my license plate.