I purchased a 91 B2600i 4x4 a couple months ago with a blown head gasket. Put in a new head, spark plugs, wires, cap/rotor, air cleaner and installed a cat since the previous owner had chopped it out. Went to get it smoged and the CO levels were high (7% and they are supposed to be below 1%), so it failed. I am also getting horrible gas mileage (14mpg) and the check engine light randomly comes on. I am wondering if they are all related. When I checked the codes it gives 1 long, then 7 quick blinks. Which according to http://www.avproecm.com/errorcodes.htm is error code 17, Internal ecm feedback system. What does that mean? Could that be the cause of my car running to rich and not passing smog? To fix that does it mean getting a new ECM? Any help would be appreciated.

 

I don't remember if I got that error code but I did let Avpro repair the ecm out of my 90 1/2 B2600i over two years ago. So far no more ecm problems. Not trying to tell you what to do but if you could be without the truck for 4 or 5 days I recommend sending your ecm to Avpro.