I hate buying used vehicles! (SES code nightmare)
02-13-2009, 07:38 PM
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I hate buying used vehicles! (SES code nightmare)
I am writing this to tell everyone my story (it has a happy ending). Had a 2001 F150 4.6L Supercab that I absolutely loved, but since my kids are getting so big, I decided to sell it and upgrade to the Supercrew model.
I found one almost identicle to mine (also 2001 4.6L V8) at a smoking good price, but when I test drove it, it flashed check engine light and ran terrible. Drove it back immediately, the used car guys explained that the truck was just listed that day and that the engine had just been washed and that the plugs were probably wet. I came back 2 days later, and the engine ran fine, but the service engine soon light came on again during that test drive. I liked the vehicle because it was cheap and had all the features I liked, but was a little skitish. I put a deposit on the truck provided they fix the SES issue. The guy had someone replace the 02 sensor, I gave it a test drive and it ran great, so I bought it.
48 hours later (after I owned it as is) the SES lights came back on and the engine was running really really bad (misfiring and hesitating) I used my code reader and got an P0402. Using advice from the forums I 1st changed out the DPFE (bought from autozone). The SES light did not go away, but I did start popping an occasional P0307 code. I then figured is was the EGR valve or a bad plug/COP. I took off the EGR valve and sprayed it with throttle body cleaner, but I was pretty sure this was not the problem, since it wasn't too dirty. Next, I tried to change out the #7 COP/spark plug. I could not for the life of me get the nut off the #7 COP, so I took it into the mechanic, and they said if I paid for a diagnostic ($79), they would put in my part if that was the issue. They diagnosed it as a bad #7 COP, so they actually gave my spark plug back to me and put on my COP (bought from Parts America). Engine started running great, but as I pulled away, more SES codes. I was now getting an p0181 and a p0401 (the complete opposite of what I was getting before) I took it back to the mechanic, and they said I needed to get a factory DPFE and to get rid of the crappy autozone one. I tried to go to autozone to swap out for factory, but they only had the knockoff, so I swapped it. But I was still getting the two new codes. I decided that it probably wasnt the DPFE.
So back to the forums I went. I now diagnosed the issue as either clogged EGR ports or a MAF issue. I peeked into the throttle body without taking it off, and it was super clean inside, so I figured it must now be the MAF. I had stolen my K&N filter from my old truck, cleaned and oiled it up, and put it into my new truck. I read that the oil could cause issues with the MAF. Anyway to make a long story short, I cleaned the MAF using the high dollor sensitive electrical parts cleaner and wiped the excess oil off the outside of the K&N filter, and finally I have no more codes and the engine is running great.
I was pretty happy to get this accomplished considering I basically have never done more than change air filters in any of my previous vehicles. Thank goodness for the internet and forums like this one. I probably bought the truck $2000 below normal market price, and I have $200 total into getting the engine right. Part of the reason I am writing this is because I see lots of people post issues and lots of people post advice, but its not often that anyone posts after they have resolved their problems. Its been a rough 1st week of ownership, but barring any more problems, I think I have the potential to love this truck too.
On the fun side, I have also added a Undercover Tonneau cover (Craigslist), a Billet Grille (Ebay), and running boards (Craigslist).
I found one almost identicle to mine (also 2001 4.6L V8) at a smoking good price, but when I test drove it, it flashed check engine light and ran terrible. Drove it back immediately, the used car guys explained that the truck was just listed that day and that the engine had just been washed and that the plugs were probably wet. I came back 2 days later, and the engine ran fine, but the service engine soon light came on again during that test drive. I liked the vehicle because it was cheap and had all the features I liked, but was a little skitish. I put a deposit on the truck provided they fix the SES issue. The guy had someone replace the 02 sensor, I gave it a test drive and it ran great, so I bought it.
48 hours later (after I owned it as is) the SES lights came back on and the engine was running really really bad (misfiring and hesitating) I used my code reader and got an P0402. Using advice from the forums I 1st changed out the DPFE (bought from autozone). The SES light did not go away, but I did start popping an occasional P0307 code. I then figured is was the EGR valve or a bad plug/COP. I took off the EGR valve and sprayed it with throttle body cleaner, but I was pretty sure this was not the problem, since it wasn't too dirty. Next, I tried to change out the #7 COP/spark plug. I could not for the life of me get the nut off the #7 COP, so I took it into the mechanic, and they said if I paid for a diagnostic ($79), they would put in my part if that was the issue. They diagnosed it as a bad #7 COP, so they actually gave my spark plug back to me and put on my COP (bought from Parts America). Engine started running great, but as I pulled away, more SES codes. I was now getting an p0181 and a p0401 (the complete opposite of what I was getting before) I took it back to the mechanic, and they said I needed to get a factory DPFE and to get rid of the crappy autozone one. I tried to go to autozone to swap out for factory, but they only had the knockoff, so I swapped it. But I was still getting the two new codes. I decided that it probably wasnt the DPFE.
So back to the forums I went. I now diagnosed the issue as either clogged EGR ports or a MAF issue. I peeked into the throttle body without taking it off, and it was super clean inside, so I figured it must now be the MAF. I had stolen my K&N filter from my old truck, cleaned and oiled it up, and put it into my new truck. I read that the oil could cause issues with the MAF. Anyway to make a long story short, I cleaned the MAF using the high dollor sensitive electrical parts cleaner and wiped the excess oil off the outside of the K&N filter, and finally I have no more codes and the engine is running great.
I was pretty happy to get this accomplished considering I basically have never done more than change air filters in any of my previous vehicles. Thank goodness for the internet and forums like this one. I probably bought the truck $2000 below normal market price, and I have $200 total into getting the engine right. Part of the reason I am writing this is because I see lots of people post issues and lots of people post advice, but its not often that anyone posts after they have resolved their problems. Its been a rough 1st week of ownership, but barring any more problems, I think I have the potential to love this truck too.
On the fun side, I have also added a Undercover Tonneau cover (Craigslist), a Billet Grille (Ebay), and running boards (Craigslist).
Last edited by Crackerjackk; 02-13-2009 at 07:49 PM.
