After trying various combinations of spacers and steel wool for months without success I finally passed emissions and got my Pa. inspection stickers. I've talked to a few different forum guys and finally decided to fab up my stock cats and give that set up a try. Problem was, right after the cats were finished the car went into "limp mode" with "trans over temp and sevice 4WD" on the dash and a U0101 code stored. So I loaded the stock tune back in the Jeep and took it to the dealership right after the cats were mounted. They diagnosed it as having a bad ESM that was replaced under warranty. The tech asked me if he could keep the car and drive it for a day to make sure the problem is corrected and I agreed. The next day he calls me back and tells me that all is good except I'm 7 months overdue for inspection. He then asked if I want him to inspect the car because it has enough miles logged from driving it. Of course I said hell yeah. It passed, no problems.(and at the dealership no less). He told me I had a few stored codes (the O2 sensor slow response codes) and he recommended that I change my O2 sensors. Apparently it takes multiple "trips" of these codes to set off a CEL. So I'm waiting on four new O2 sensors but in about 1500 miles of driving since I installed the stock cats, I've tried the stock tune and one that Johan did and another done by Ed Hutchings and they all work. I'm still "ready". The stock tune works surprisingly well with the TB ported intake and headers. It's so pig rich that I only see high 11's at WOT. (which would probably be in the 12's in cooler air). The stock cats have a 2 1/2" pipe inside the 3" outer pipe. I left the inner pipe in one of the cats so I could try one with and one without the inner pipe in case that made a difference. It doesn't seem to matter so removing the inner pipes would be the way to go. The stock cats don't hold back as much as I thought they would at WOT compared to the high flow cats. At less that WOT I can't notice any difference except that the stock cats are quieter. The stock cats are wider but have just enough clearance for mounting side by side with the SW set up. I have a set of off road pipes fabbed as well and with V-bands up front and the stock clamps at the cat-back. It's literally a 10-15 minute job swapping back and forth. I gotta thank Harrison for all of his turbo pics which is where I got the "V-band" idea from. And thanks to my bro Jose for all his input on this project with me.
Real nice job Rich!!! Looks like I will be making up the same mids with my stock cats as I need to pass emissions in January... Them foulers are too much of a pain in the a$$ bro.... Now there is no excuse why not to get headers installed...
Thanks man. I gotta thank Jeff at First Try Engineering for the execution. Big thanks to Anthony at Stainless Works for keepin my midpipes in the corner of his office for 6months. Lol
Very nice and congrats for finally passing inspection with headers.
What year is your Jeep?
So basically anyone that has headers and mid pipes with stock cats will not get a CEL?
Man... this issue about not passing inspection have been holding me back in getting headers for so long...
Has anyone else done this before with a different brand of headers?
Thanks for all the valuable info.
Your welcome. My Jeep is an 08 but I can't see why it wouldn't be the same for all years and for any header system. Just different fabrication. The O2 sensors are going to see the correct back pressure so that seems to be the critical issue. My O2 sensors need replaced and I'm still "ready".
Congrats on getting through inspection. I remember someone else mentioning that people should try the stock cats just like that a while ago but I can't remember who that was....
I know I brought it up at one point in the past! Just didn't have the money/balls to give it a shot. Glad it worked for you, now I can't wait to try! Nice job.
Thanks.The guys that will benefit the most are the guys buying headers. Now they can just buy the off road mid pipes and fab the stock cats. My cost was about $500 in parts and labor but buying non-catted LT headers saves roughly $300 off of that.
Very nice and congrats for finally passing inspection with headers.
What year is your Jeep?
So basically anyone that has headers and mid pipes with stock cats will not get a CEL?
Man... this issue about not passing inspection have been holding me back in getting headers for so long...
Has anyone else done this before with a different brand of headers?
Thanks for all the valuable info.
Congrats on getting through inspection. I remember someone else mentioning that people should try the stock cats just like that a while ago but I can't remember who that was....
I know I brought it up at one point in the past! Just didn't have the money/balls to give it a shot. Glad it worked for you, now I can't wait to try! Nice job.
Yeah, they make the exhaust sound really sweet at anything over 1/2 throttle. Without the restriction of the cats, you can feel the difference on the top end too. I put the rear O2's in them last night and drove to work today and the set up works perfectly. The tune has the rear O2s "off" for the off road pipes.
Kudos to you, Rmon. This and BuilderBill's experience seems to affirm that this is the only reliable way to make headers and the O2 sensors happy for the '07 and up crowd. Subscribed, and looking to do headers in the future.
Jeezuz, seriously? So with cats in my midpipe I need 24" extensions installed for the rear O2's, and extensions for the front O2s as well ? I dont know where these things are in the stock locations. Whats the point of tuning out the rears if you still get a code ?
My impression is that turning off the rear O2 sensors eliminates their feedback to the PCM so that they don't "see" parameters outside of their specified guideliines. Eliminating them shows what is essentially an "open" circuit that HAL doesn't like and unfortunately it can't be tuned out. Maybe an expert can chime in with opinions and/or a better explanation.
As far as the ball clamps that attach the rear of the cat to the cat back flange, SW doesn't have a part number but Anthony Grosser will know what you want and they will make them up custom for you. You just want the end pieces in the illustration behind the off road pipes with the O2 bungs.
Johan said the same thing to the guys out at ESP (my local shop) when they were trying to get the Hennessey Jeep to pass inspection. Johans "way" was to make the rear 02s say "not supported".......which is not legal here in MA. The Hennessey failed the test, and was flagged by the state in the registry computer.
Kooks says the green cats are 98% effective. With my luck, I'll be one of the 2%. $700-$900 is a lot to spend on green-cats, and I'm not even 100% sure it will work.
Why don't you just get your factory cats setup with flanges and use them rather then the kooks? They are free and probably more efficient then the kooks anyway. Just a thought....
Why don't you just get your factory cats setup with flanges and use them rather then the kooks? They are free and probably more efficient then the kooks anyway. Just a thought....
I have an extra set of Kooks off-road pipes I can use to make a set of mids to pass inspection. I was afraid to cut apart my factoy mid-pipe, because if the truck doesn't pass for some reason, I would have cut up my only means to pass inspection. I also wasn't sure how the funky shaped factory cats would fit under the truck, or if it would just be easier to use 2 brand new cats. My friend owns an exhaust shop, and is a Magnaflow dealer, so I can get 49 state legal cats for cost.
I thoght people had tried welding in legal cats into their LT mids before, and it didn't work.