I've got a 2007 Dodge Ram Quad Cab with a 5.7 Liter Hemi in it. It has 52k miles on it. I just had dual exhaust installed, behind the cats & oxygen sensors. The cats or oxygen sensors were not tampered with at all. However, after driving approximately 40 miles, my check engine light came on. The code pointed to the cat on the #2 bank. The muffler shop cleared the code, hoping it was a fluke. However, after driving approximately 60 miles, another light; same code. Is it just a wild coincidence that my cat just happened to go bad at 52k miles, or did putting true duals on my truck screw something up? How can this be fixed?

 

Very low tolerance on most of the newer PCMs for anything out of spec when it comes to emissions. Since you just paid good money for exhaust work and I'd assume the company is reputable, I'd make them fix it. Tell them you want sims (simulators). They probably won't do that for you without an extra fee, cause sims ain't cheap at probably like close to $100 a pair. You can always have them do non-foulers. Do a search here, lots of posts, probably at least a dozen just by me. I think I also did a "DIY" in that section with pics. But anyway, they'll work and cost about $5 per side (have them do both sides, no sense taking a chance having a CEL come up on the other later). Anybody that's been doing exhaust work for more than a week knows how to install non-foulers, I'm surprised they didn't just go ahead and do it when you popped the CEL the first time.

 

https://dodgeforum.com/forum/diy-do-...ving-cats.html

 

pretty good info to know

 

Hammer - I just read that DIY. I had no idea that was an option. SO with that setup, you can completely remove the CATs? are there any other side effects (negative or positive) of removing the CATs?

 

Only if you need them will you find hardship without the cats. Hell, if you don't need them, you could have had them run true duals right off the manifolds. You have just duals, not true duals. Either way, some hand held tuners can turn the rear sensors off. I had a pair on my mustang that ran me $50 for the pair. Plug'n'play.
Removing the cat will result in mild gain. Nothing substantial at all.

 

Agreed, I really don't see a benefit in getting rid of a properly working cat. I posted a few days ago in another thread, that cats today are not the cats of 20 or even 10 years ago. They are not that restrictive at all anymore, again, when in proper working condition.
So, yes, using the non-foulers or sims will allow you to run with no cats and not generate a CEL from the rearward sensors. But again, unless you've got a clogged up, non-functioning cat and just don't want to or can't afford replacement, I see no benefit of cutting out the cats. Hell, I've got LT headers and I still run the factory cats...

 

My1st: I'm going to go ahead and answer your email right here in the thread so others following can get the information.

And yes I suppose you would be a little sick over it. You pay a place good money for increased performance and pop a CEL.
Been there, done that. Most of us have.

I trust you read my DIY on the "non-foulers" L & R was kind enough to provide the link to, if not, do so as it will completely explain what they are and how they work.
As far as "sims", they are 02 simulators, nothing more. Instead of working with your O2 sensors to eliminate the condition that is causing the code to pop, they replace your 02 sensors. They basically send a signal to the PCM stating that you have cats, and all is well. Because they are IC's, they are not near as inexpensive as the simple non-foulers, but if they are manufactured for your specific vehicle, insuring the proper signals are sent to the PCM, they are fool proof.

But again, I'd dump it on the lap of the shop that did the work. The reason you pay good money to have this work performed is for their expertise. I do almost all my work myself, but I'm not a trained mechanic by any means. As I get into more higher end performance mods, I will have no choice but to pay a reputable performance shop for the work. This won't be cheap, and believe me, if their work is not up to my specs or I have a CEL pop, you better believe I'll have my a$$ down there in a heartbeat until they make it right!!!

 

thats why we call him the hammer lmao... great info on exhausts.... its amazing how much repition of discussion goes on in these chats lol..... exhaust work is also the most fun to work on..... because you get to weld yay

 

hey hammer question.... what do u think of LT headers versus Shorties? whats the better choice? I always prefered lt's but maybe im not being open minded