Hello,I just recently picked up a 98 ford Explorer with 141,000 mi 4.0 OHV, I went to warm it up in our first snow storm yesterday and noticed when I got back in the check engine lite was on. The codes that came up were 0171, and 0174, any suggestions on this? I tried to do a search but no luck. My buddy @ ford said that these higher mileage 4.0 intake manifold upper and lower gaskets may have to be changed, that's probably what caused this, it stills runs the same, I just want it to be right without causing any damage.

Thanks.

 

http://boardreader.com/t/M_17780/Cod...74_587063.html


same problem on this site with some explinations

 

Good information thanks!!

 

That is correct, I just changed the intake gaskets on my 2000 4.0. had the same codes. It runs like new again. The gaskets are rubber like o-rings. Mine were hard the new ones were soft so they seal better. Just make sure when you change them you clean all the surfaces good. Mine had some sand on the manifold I had to clean off.

 

I was wondering if you just replace the upper gaskets or did you do the lower as well?