Old Explorer, new questions

[Donald P]

Hi guys, new to the forums. I recently picked up a 97 XLT 4WD with a SOHC 4.0 for $500 with 161k on it- and it needed some work but so far I've done the upper and lower ball joints/control arms, replaced the hubs, replaced the rear diff gasket, replaced the headlight buckets (too hazed to save), cleaned and lubed the spare hoist, saved the VAP bracket from a doom of rust, and other odds and ends. Still have a few tasks left but she runs good.

I've searched the forums and found tons of answers and info for a lot of the questions I have had so far but so far a few still escape me. If you guys could lend some knowledge it would be greatly appreciated.

The muffle is shot and looking at the exhaust system the pipes look pretty bad. What puzzles me though is it appears I have no cat converters. The manifolds go into two downpipes to the huge muffler and exit in a single pipe to the resonator. I haven't been able to find the O2 sensors and I'm not getting a CEL. Is this a normal setup?

Also when I pulled the engine cover to clean the throttle body and IAC valve the black plastic VIS "butterfly" was completely off it's shaft as if it had just popped off. I put it back on and haven't noticed any difference whatsoever. Is this thing crucial to the engine and is there a test procedure for it?

 

[drdoom]

That does not sound right and I have that same rig.

 

[drdoom]

As for the VIS actuator, mine was the same way. I picked up a 1/8" e clip and put that back on about forty yhousand miles ago, it has yet to fall back off.

 

[Donald P]

After looking at it again a couple of times today I believe that the CAT has been taken out of the loop because the pipes definitely do not have factory welds on them. Here in Arkansas it seems to be kind of a common practice to bypass them when they go bad, however as this Ex is headed to Texas it's going to have to have one installed due to the state inspection criteria.

Next question: Would it hurt to run those two pipes into a Y running into a single pipe universal cat and back to a thrush muffler without a resonator in the end of the system? I'm trying to get out as cheap as possible on this (the Ex is for #3 son at college and we're looking at it lasting at least two more years).

Thanks!

 

[SoNic67]

It might not pass Texas emissions because it will not be stock setup.
Anyway, I wonder how they bypass the O2 sensors, probably something stupid like this.
And yes, probably you get crappy mileage now, running in "open loop" all the time.

 

[Donald P]

I did some digging last night and if you replace the original setup due to it's being missing as long as a cat is there it's OK in Texas. Apparently with the level of CAT theft they experience having something else other than the stock setup isn't frowned upon as long as it's there.

The route I'm thinking about going now is to take a masterflo 2.5" in 3" out Y pipe and run the existing pipes into it and coming out to a walker universal CAT then back to a thrush muffler. Any comments on that setup?

 

[SoNic67]

So you will plug the two O2 pre-cat sensors in the Y pipe?

 

[Donald P]

I've got to go out and get under the ex again because my brother swears he saw O2 sensors on the upper pipes. If worst comes to worst I may just end up plugging in a pair of magnaflow universals into the current pipes and replacing the existing monster muffler with a regular dual in single out. It's looking like I'm going to end up with 2x Cats for around $100 each and a replacement muffler and pipe for around $150 or so.

 

[SoNic67]

I've got to ... get under the ex again...

That sounded so... interesting, until that point...
:roll: