Originally posted by martinjose
zenpal,
Just floor it in park. If you see black residue on the ground after this, that is carbon. Plus, run your finger through the end of the muffler, if it comes out very black, carbon residue. When I bought the truck, the muffler was clean of carbon. Carbon residue started when the SES light came on.
I took my vehicle to the ford shop for dianostic since the O2s fixed didn't help. They found the PCM had a short causing the fuel injector to push to much gas. Luckly, the PCM is covered under Ford emission system warranty. 8/80, so no charge to fix it. Lucky me.
Hope this helps.
Before you guys go any further, read the Expy Owners' Guide that our moderator has put together. There is an article that talks about your PCV valve & hose repair. Check it out, this inexpensive fix could solve alot of big headaches. The problem has been known to kick out DTC codes for O2 sensors, so it is worth a try.