Hey guys. Drove the old Jeep first time to smog. Failed. Anyone know of a good smog and repair place in the Sacramento or Elk Grove area for older vehicles? Jeep 4.0's. I have a 1990 Jeep Cherokee. Thanks

Update: included smog test and I put an aftermarket walker exhaust. It was sold said as CA CARB compliant and the numbers are in the yellow picture and I can look on air resources under the pre OBD2 list and csn find it, but for some reason, the smog place Said no it was not carb compliant. The cat is brand new with less than ten miles on it. I have replaced just about every item.That can be easily replaced.And I thought i've checked all the vacuum hoses. New fuel system from the tank to the fuel regulator with new injectors and new Ignition with coil and spark plugs. And cleaned out the throttle body. And you name it. I probably replaced it, but I'm not sure about the fuel injectors if they're correct. Smog said that it was burich.Which means it's burning a lot of fuel and you can see the numbers so I'd like to look at things first and figure it out before I take it to somebody and spend the money. Thank you and appreciate the help.

 

So first, I assume the D-193-104 is the EO number off the cat. It may be CARB compliant but it's not designed for your XJ so that's a fail and the "TAMPER" and "modified" result.

The CARB certified CAT must be the one certified for your XJ.

You can look up the proper EO number and Part number here (sounds like you may already have the link).

https://ssl.arb.ca.gov/AftermarketParts/catalysts

You can do a vehicle search, find your XJ, and see all the CATs that are OK. Make sure any CAT you buy has the correct EO number and part number.

You can also lookup the EO number. When I did I did not see Jeep Cherokee anywhere on it. I do see D-193-105 as listed for the XJ

Next, you are running very rich. Most likely it's a bad O2 sensor but could be something else (like a leaky injector)

You also failed the EVAP test. Looking at your results it says you have a bad gas cap. Don't think I ever saw one fail "visually" so it must be in bad shape or missing the gasket. It also failed the functional test. That's where they hook it to their tester and pressure test the cap. They then also pressurize the tank to test the evap system and look for any leakdown.

Can't say why your "Fuel Evaporative controls" and "other emission related equipment" are marked defective. Make sure the lines going to the canister are connected and have no cracks or breaks. Check the fuel intake and vent line going from the tank to the filler neck. You might need to do a smoke test. Also check the rats nest of vacuum lines on the manifold.

Other than running rich does it run ok? Does it idle OK?

FYI: Car Sound Exhaust Systems is Magnaflow.

 

I just did mine in June. I did a lot of work to it in order to pass in 2020 (failed the first time). It's passed in 2022 and 2024 on the first test. Here are my 2024 results for reference.

 

Also, hard to tell from your picture, do you have the preheat hose that goes from the exhaust manifold to the front of the air cleaner? I had 2 vehicles fail (one was my XJ) back in 2014 because I didn't put that hose back on after doing some other work on it.

While I'm on a roll, make sure your TPS is adjusted correctly.

 

Apparently it's new to you xj with 270 k failed hc and co by a lot.

Hc: check the compression, if it's low, burnt vave or whatever you have a problem.

CO: you didn't mention if the O2 sensor has been replaced

The new catalyst
With those Hc numbers it's almost like the cat isn't doing anything. Is it a reliable brand or an ebay special?

You absolutely need to make sure the injectors are about the correct flow.

 

Injectors i'm not sure about. Oxygen sensor is brand new. Gas cap is new. Preheater hose is new and connected. The engine idel's perfect.And I have no hesitation.Or rough idol and it's got a lot of get-up-and-go.And I ran it at 50 and 55 miles an hour in traffic with no issues.And the temperatures stayed fairly down on a ninety five degree day. You do smell the exhaust. The Walker CAT that I'm using. I thought showed on the a resource bored page. But I will have to go through it again and speak to them directly to make sure period but if you believe that. Academic converter is the wrong size.Size for the jeep , then I will find something that is correct. That will be the.First thing I do and get the exhaust corrected once.I verify and then I'll go from there. I appreciate the input.

 

Follow up on the CAT. I purchased the wrong CA compliant CAT. It is a Walker but it is listed in our state as a CAT that is supposed to be #1 of 2 CATS. So I am assuming that this CAT is not adequate and therefore could contribute to a little?? or a lot?? of the issue (theoretically)? I am in unknown waters when talking about this stuff. Thanks

 

Sorry to nit pick, but what brand O2 sensor? Our old Renix seems to do best with NTK/NGK ones. I used to always used Bosch but was replacing them almost every smog check. Switched to NTK (back in 2020) and have passed the last 3 smog checks.

Do you have a bunch of oil in your air cleaner? Excess blowby ends up in combustion through the CCV valve.

I have the Walker Cat on mine. PN 80945 It's a direct fit (bolt on). EO D-182-55. Installed back in 2014. Not a log of miles in total on it, but lot's of short drives. Still working.

Not sure what you mean by 1 of 2. Our years have only a single cat and only 1 O2 sensor..

 

Well the Walker Cat I put on is a D-193-104. It is meant to be paired with another CAT if you have a single bank- 2 CAT system. So I have the wrong CAT. I have a Bossh O2, brand new. No blow back, no oil in filter. I will have to change it. The CAT you mention you have will not work in CA. It is not listed here on our state page. State has to approve the CATS for various things but the big thing that restricts so many of them is a longevity test which most end up on the can not use list. I am going to pick up the MagnaFlow CAT that is approved and I can find anywhere here. It seems to be the cheapest also. Not cheap to me though.

 

Not sure what list you're looking at but the one I listed IS on the CA approved list (3rd page). It's the same for yours. Magnaflow makes excellent cats too.

If it were me, I'd get the right cat, check for exhaust leaks, double check your TPS adjustment, take it for a good drive (to make sure the cat is up to temp) and go get retested to see how the numbers change.




Keep us posted. You'll get there!!

 

https://ww2.arb.ca.gov/pre-obd-ii-ca...ification-list
My walker is a T2 or for truck but with 2 CATS. It is a 334004 and does NOT fall under the executive order (link) D-193-104.
The Magnaflow is the same price everywhere and easily available at my parts store, so I will get one today.
I have a Ag machine shop which did my work last time (I had the exhaust hitting my transmission cross brace, so we moved, tightened and welded away from it. I will have them look close since they have a lift. If I have a manifold leak, I will see about doing a new one. I guess I will change the O2 again since that is the only thing on my end that makes sense other than vacuum leaks. I have not adjusted the TPS nor have done that.

 

I have another question. Has anyone figured out an alternative to the discontinued EGR valves for the 4.0? I am in one of those blue states so I can not delete it. Can they be fixed or refurbished? I am not sure if mine is bad but if it is, where do I go?