Originally posted by Robert
My '97 developed the problem in March of last year when I had around 50K-52K on it. It was the coldest spell of the year here in Phoenix. I had noticed all winter that my idle seemed to bounce from 600-1000 RPM when I first started it in the morning. In March, my Check Engine light came on. I had my light come on about 10 months earlier when traveling across the country pulling a trailer. I pulled the battery cable off at a rest stop, and didn't see the light again until March, 99. My light came on less than a mile after leaving work one afternoon when the temperature was in the low 50s. When I got home, I disconnected the battery thinking it was probably just a glitch again. About 1 1/2 weeks later the light came back on. I disconnected the battery again, but this time the light came back on 2 days later. Since I was well out of warranty, I bought an OBD-II scanner figuring I would get a lot of use out of it in my Explorer anyway. Read the codes and got a P0171 set as a trouble code and a P0174 as a pending code. I checked out Alldata.com for TSBs and found a TSB that had both of those codes listed (along with a couple of other ones). The TSB attributed it to leaking lower intake manifold o-rings. The procedure to verify it was to inject propane in around the manifold while monitoroing the short-term fuel trims. When I sprayed the propane, the fuel trims would change by about 50%. Take the bottle away, the fuel trims would go right back to where they started at. It matched the TSB to a 'T'. I took it to a shop and had Warranty Gold pay for new o-rings. I didn't think it was a common problem until I started seeeing many posts from people with the SOHC V6 with the same problems. For all of them, the fix was replacing the o-rings. Then when Ford came out with their Owner Notification Program (00M12), it became very obvious that it was a lot more common that I at first thought. I see 3-4 mew posts a week now from people with the same symptoms. The common items are SOHC and 40K-60K miles. Fortunately for me (as well as many other Explorer owners) Ford also included the rattling cam-shaft tensioners in the same program. My Explorer had been sounding like a diesel for the last 1 1/2 years, but since Warranty Gold has an exclusion for fixing any item that the manufacturer has issued a TSB for, I wasn't going to try and get them to replace my tensioners to fix a noise that Ford still says is only "cosmetic" and causes no harm.