Removing Cats

RedRamRules

RedRamRules

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If I were to delete the cats without adding sims, how long can I use my truck before it gives me problems? I assume I would maybe run too rich or start to lean out due to no feedback. I am aware I would see the engine check light.
Also would any tuning software (like AEM) be able to give appropriate feedback to the computer without the addition of sims? Thanks.
 
I can get some midpipes welded for 50 bucks, which is cheap enough for me to jump on. The sims I would like to add later until I can save a couple of bucks. Just wanted to know if I should just wait for the complete package first. Thanks OCBob.
 
Hey Juan,
I would wait for the complete package if I were you. I would think the sims can't be all that expensive.
 
Your going to need the sim's. And your going to have to drill and tap four new holes in your mid-pipes to receive these sim's..... not cheap! lol

Quick
 
You will need to reinstall the front O2 sensores no matter what. If you don't install the rear sims you will get a code sooner or later, it should still run fine for a while.

Bill.
 
Begood said:
You will need to reinstall the front O2 sensores no matter what. If you don't install the rear sims you will get a code sooner or later, it should still run fine for a while.

Bill.
Click to expand...
Yeah, I was wondering if running a couple of weeks without sims could cause any damage or have side effects. Thanks for the help guys.
 
Juan bro, you need the pre-cat o2 sensors no matter what. This is what your pcm reads off to determine wether the engine is running rich or lean after it is in closed loop. the rear o2 sensors you can leave out as these are only for monitoring catalysts efficiency. The o2 sims plug right into the harness where the rear o2sensors would plug in. you will go 3 drive cycles before the check engine light comes on. the sims are 150 from boomer. Oh and just some advice, 50 bucks seems cheap, too cheap. Also if your considerin leavn the oem midpipes intact(which u should) your goin to need to make some new flanges. All in all, hold off and take a look mines when i get back. If you like em i'll let you get for what i spent plus a little labor. Honeslty i recommend you get the ones that are being sold here for 500bcks.
 
FerrariTruck said:
Juan bro, you need the pre-cat o2 sensors no matter what. This is what your pcm reads off to determine wether the engine is running rich or lean after it is in closed loop. the rear o2 sensors you can leave out as these are only for monitoring catalysts efficiency. The o2 sims plug right into the harness where the rear o2sensors would plug in. you will go 3 drive cycles before the check engine light comes on. the sims are 150 from boomer. Oh and just some advice, 50 bucks seems cheap, too cheap. Also if your considerin leavn the oem midpipes intact(which u should) your goin to need to make some new flanges. All in all, hold off and take a look mines when i get back. If you like em i'll let you get for what i spent plus a little labor. Honeslty i recommend you get the ones that are being sold here for 500bcks.
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Cool, let me know when you're in town, I would like to take a look at your setup.
 
QUICKSILVER said:
Your going to need the sim's. And your going to have to drill and tap four new holes in your mid-pipes to receive these sim's..... not cheap! lol

Quick
Click to expand...

Nope. Just two for the pre-cat O2's.

As was mentioned, the sims just plug into the harnesses.
 
I have the Mopar cattless mids, they come with the bungs for all 4 sensors to go back into. Like mensioned earlier the front 2 are the ones that the ECM uses to control fuel, the back 2 are to monitor the cats for problems. I ran with the mids and not sims for a couple of months and never got a code. Now I have the Mopar ECM which I asume ignores that back 2 sensors.

Just had a thought, why can't the guys doing the flashes trick the ECM in the programing and not need the sims. I guess then they would be cheating themselves out of selling the sims ;)
 
i think 50 bucks is a reasonable price depending on the material used.... there is no way on earth that they could possibly be worth 500$ or anything that crazzy... i had an entire dual exhaust system built for an old truck of mine cost me $300 from the headers back... but it was only for a low hp 8cyl so it was only 2 or so dont really remember and it was somekinda cheep material not stainless steel but still it was 2 low to see the underside anywya and its been good for the past 10 yrs...
 
I made some mechanical sims for my hemi with Spark Plug fowlers. They cost about 4 bucks for two pieces at AutoZone. I used 3 pieces per plug, so 12 bucks. Plus I put in some standard washers to slow the flow of air down. I would have used electrical sims, but nobody has broken the code yet for the hemi's. Anyhow, it has been about 400 miles and no check engine light. My first try was with only 2 pieces and no washers and still got CELs.
 
I cut the cats off,gutted them out and rewelded them up,no codes,I asked the questioned once before,as long as you have the 4 bungs,do you need the sim's I never got a answer,but I have not thrown a code yet,did this mod a few months ago!
Bill
 
gearheadbill said:
I cut the cats off,gutted them out and rewelded them up,no codes,I asked the questioned once before,as long as you have the 4 bungs,do you need the sim's I never got a answer,but I have not thrown a code yet,did this mod a few months ago!
Bill
Click to expand...
Thats what I had in mind, removing the cat only and leaving the bungs intact. Is it possible for you to take a pic underneath. Thanks for your help.
 
RedRamRules said:
Thats what I had in mind, removing the cat only and leaving the bungs intact. Is it possible for you to take a pic underneath. Thanks for your help.
Click to expand...

:dontknow: It would look like stock, he gutted out the stock cats and welded them back in.
 
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