Finished putting in New Plug Wires, new Plugs. Took it for a test run. Runs really strong. Maybe psychological, but seems to run and idle better. Motor has a lot of miles but been changing oil etc regularly. And it just feels good running around the neighborhood. I may try the pre test again tomorrow. Have to see if I can play hooky for a few hours from work. Then see.
Anything else I can be checking? Oil newly changed with maybe 100 miles but the Jeep has sat in the garage for a couple of months. Did start, run it around once a week or so. The coolant needs attention. But want to try pre-test smog first. I have a local mechanic that has in the past done well with cleaning fuel system out for my other cars. Not the quick lube places but an actual mechanic I do trust. If it fails smog but close, I'll do the fuel system clean.

 

Sounds like a good plan. I'll bet it's not psychological that it runs better......

 

Failed smog but better.
I ran with the original O2 Sensor. I have a NTK (Made by NGK ) I will put in. But a mechanic I know and trust likes Denso but no real preference for Jeeps. . Didn't I read in this forum that NGK/NTK are preferred? Asking if i should stick with NTK I have rather than exchange with Denso.
I'll post my results next

 

 

NTK hands down. Use it.

 

Since I have the NTK/NGK O2 sensor, I will.
What do my results show. For this smog test, I did put in a new Catalytic converter, new plugs, new spark plug wires, Brand new rotor/cap (has Aluminum contacts but brand new). But has the old O2 sensor in it. I switched back to the old O2 Sensor because I had put in a New Bosch O2 in it and read that Bosch not so great for Jeeps. And the results with the Bosch O2 were not good.
HC Passed both 15mph and 25 mph. CO passed both 15 and 25 mph. But NOx high for both. It is an aftermarket catalytic converter from a shop in La Puente, Ca that I have used and trusted in the past for my other cars. But are Jeeps really fussy? It is a CARB approved Catalytic converter. Last thing I think can change is O2 sensor and then exhaust manifold?
I'll change O2 Sensor and see what happens. Tighten up the exhaust manifold bolts if I can reach them.
Will also do another exhaust leak test with low pressure compressed air put into exhaust pipe and feel in the engine compartment for any air.
Somewhere I read that someone put in two small 1/16 inch diameter holes in the exhaust pipes AFTER the catalytic converter to nudge the NOx results. Is that reasonable? I'll do that as a last resort before ripping out the exhaust manifold for a new one.
Other suggestions?

 

You're doing a great job. carry on.

 

I'm not thrilled with the idea of drilling any holes... not much help except to mention NOx forms at high combustion temp/pressure. Premium just might help. My NTK 02 sensor seems to work fine.
Those manifold bolts look allot easier with the air cleaner off. The back one underneath is gettable with the right extension, then for the rearmost exhaust nut use a universal right on the socket, then a mile of extensions...

Bummer! Btw. Hope you get it. When I moved from La Puente when I was 4, in 64, the smog there really sucked. I still remember not being able to take a full breath without my chest hurting!

 

I installed the NTK/NGK O2 sensor. May try test early morning if I can take off a few hours work in the morning.
See how it goes. I still have to do the air into the exhaust to check for manifold leaks test . Then see about tightening the manifold bolts too.

Heard that pouring a quart of denatured alcohol in the tank will cause it to burn 'cleaner' and pass the smog. I'm hesitant about doing that only because what it could do to seals etc....
But if to pass smog now so I can legally license it, I would do it. Then of course take care of the other things. The motor does have 243,400 miles on it. So could be some issues there.
But I'd like to get it smogged.
regarding the smog in La Puente. It is better. I used to work in Rancho Cucamonga in '89. We had two buildings maybe 100 feet apart. Go out one building towards the other, Couldn't see the building and it was 3 stories tall. Smog is much much better. Can at least breathe.

 

"Denatured alcohol" like Ethanol? Gas up here is already 10% by volume

If you haven't already, run good fuel prior to the test. These guys should be on your list of contenders: http://www.toptiergas.com/retailers.html

Some folks here have posted problems trying to pass emissions testing with stuff like Wally World and Arco fuel

 

For the smog, I have Chevron premium, 91 octane. Recommended by the shop I've used for smog.
I put in the O2 sensor. No issue. But got to looking more at the exhaust manifold. And I saw a small hairline scratch in the patch I already did. Couldn't tell for sure if it was a crack so I patched it again. I think it was so that would cause smog fails. I am letting the patch cure and will try it again friday morning. I will be replacing the manifold.
Now, my decision is whether to go buy new at Autozone or buy from salvage yard, weld up the joints and reinstall.

 

While we're on the subject of fuel, it's never a bad idea to put a can of BG44K into a full tank of gas and run it down to 1/8 tank. That stuff cleans not only the injectors, but removes carbon from the combustion chambers and tops of pistons.

 

BG44K? Never heard of it.
As far as replacing the exhaust manifold, is the stainless steel worth buying?

 

http://www.bgprod.com/products/fuelair.html

http://www.bgfindashop.com/44K.htm

 

Looks like BG44K is only at service type places? Expensive?