After clearing up all my codes except the annoying p0420, I finally got the solution to my issue and put in a new fuel pump. car seemed to run great until filling the tank with gas....ALL OVER THE PLACE UNDERNEATH! I took car home and removed this large ring that goes I believe under the lock ring, this ring was not present when I removed the ring but it came with pump..funny thing all codes cleared and car is finally ready for smog check according to scanner. After removing this ring I drove car shaking around a bit and didn't smell any additional gas odor. my question is will this clear after a day or two if what I did was correct or is something else wrong. Could be ring was cross threaded? now idle seems very high also.


2001 s type 4.0 111k miles

 

there is a green gasket that goes between the fuel pump assembly and lock ring. (Or between pump and flange seat on body - check JTIS but there is definitely a o-ring style flat rubber gasket)

I have a feeling if you didn't find it when you pulled the old pump its now sitting on the bottom of your fuel tank.

I would ensure that gasket is in place. Spec calls for that gasket to be discarded and a new one installed when replacing the fuel pump.

Also, I would also check that lock ring carefully for cracking. How did you remove? Are you sure you didn't over tighten? These lock rings are prone to cracking/breaking.

Fuel is not one area you want mistakes in, either with fuel or vapors...

 

That green gasket was discarded and the new gasket was installed, I used a method here on the forums by tapping lightly and loosening ring. I am sure its not cracked. The gasket in question was a large round one that fit under lock ring. I'm going to test it again today.

 

Then maybe the lock ring wasn't tightened enough. I used the same method but I marked the lock ring/body so when I tightened I lined the marks up so I knew it was tight enough.

Also, there's a groove where the fuel pump recesses into the car body. Check that also as if it's not seated correctly could be the cause of the leaks.

Good news on replacing that gasket. Many people skip that. It's recommended to replace for a reason...

 

Test drive proved to be ok. I will check on scanner tmrw. But no more variations to idle either. Prayfully it will be good.

 

If the P0420 DTC is still remaining in the system, the vehicle will not pass a Smog Check.

You must replace the Bank1 catalyst. Do not waste your time with replacing/swapping oxygen sensor(s) around as the catalyst is permanently damaged.

 

I'd like to end this post on a good note. My issue with the p0420 code was the pump. I rechecked my work and made some adjustments to the lock ring. I PASSED SMOG! WOO HOO . this car has never ran better since purchasing it 3 yrs ago. Thanks to all who posted their knowledge. I'm just sorry I have to turn it back over to my wife. My truck not as cool as that fine automobile.

 

H o o r a y !

 

Thermostat housing next! Any advice besides patience?

 

Aluminum housing for sure and change that short 3" hose coming off the housing ava any other hoses that are questionable...