I installed a flowmaster super 40 series muffler and removed the two resonators in the rear. and two days later i had the engine light come on. I took it to the dealer and they scanned it. The code that came up wasP0240: Catalyst System Efficiency Below Threshold (Bank 1) They checked the o2 sensor and said it was working fine and didn't hear any exhaust leaks. Two days after having the code cleared it came on again. I called the dealer and they said they were going to call there tech support and get back with me in a few days. I called them today and they said i would have to put my stock exhaust back on so they could trouble shoot the problem. I am not paying to have the stock exhaust put back on so they can check out the problem. Trying to figure out what to do.Get an 02 simulator or buy a Diablo to bypass the secondary o2 sensors. Dealers don't want to get involved. I was told by a muffler shop they have to fix the problem by federal laws. Is that true? Any ideas???

 

We had 40's put on our 09 Hemi & left the resonators on sounds great (Ferds just hate the sound) with no problems to date 36k miles & still running great.

 

Yes, but fixing it means that they will put the exhaust that the truck was designed for back on. You already had one thread on this. Did you put the resonators back on to see if you could introduce enough back pressure back into the system?

https://dodgeforum.com/forum/4th-gen...r-muffler.html

 

No i did not put the resonators back on. I talked to the speed shop that did my exhaust system and he said it would be the same as buy a full cat back set-up. I have seen other Rams with the same set up as mine and they do not have any problems. Wouldn't it be better to have less back pressure?

 

Less to a point, is good. Gas engines must have BACK PRESSURE... Your computer is looking for more than you have, you'll just have to find the right amount to give it. Something with other trucks must be diff. or they would have a code???

 

So if i put my resonators back on do you think that might solve the problem?

 

As others have stated, Dodge would cover the repair under warrenty if the problem was being caused by the orginal exhaust system. You changed it. They are not responsible for what problems after market parts may cause, especially when the parts are not equivalent to the original.

 

To answer your question ELDZ06, I have the 40 series flowmaster on my 09 Sport with NO problems. But, I kept my cats.If you put the cats back on it should work fine.

 

You mean the resonators. I never touched the stock cats. Is this what you meant?

 

Sorry about the mistake, yes I mean resonators.....