Rear O2 sensors / Full Flow Cats

[Neubium]

First, please forgive me if this topic has been raised previously. I have recently purchased a 2010 SRT Challenger with a SMS Supercharger. The car has a SMS custum tune loaded via the predator. When I received the car, the full flow catayltic converters were in the trunk and the stock cats were installed. The seller informed me that he had just removed the the full flows as a precaution before heading to the inspection station. I received the car and drove for 3K miles with the stock cats. Yesterday I installed the full flows to see if there was much difference. I figured the custom tune was applied with full flows and figured it was the right thing to do. Almost immediately, I received the engine light with O2 related codes. I reset the trouble codes with the predator but they returned after 30 miles of driving. I have read that the rear O2 sensors can be disabled, but I did not see a link with the predator to get you there. What do I need to do? Please help.

Thank you

[Mike_Levy]

You need to contact a CMR dealer to turn them off. You can't do it with the Predator. Also be aware that it is NOT legal to mess with emissions equipment (which is why the option was removed from the Predator). As has been stated before, the EPA can test any car, at any time. If you fail an emissions test, you get hit with a BIG fine and the car will be impounded. Turned off O2s are an immediate fail. Try spacers first. http://www.bigdaddiesgarage.com The guy who I work on my car with had his GT500 tested on the Jersey Tpke a couple weeks back, so they are looking.

[Neubium]

Thank you very much for the information and what looks to be a solution. I will purchase the O2 sensor extenders.

[Neubium]

There have been as many as 5 codes but today just 3. The PO430 and PO420, cataylst system efficiency below threshold bank 1 and 2. Also P2098 post catalyst fuel trim system too lean bank 2.

[Mike_Levy]

The P0420 and P0430 are the ones we expect. The other one is the same one I used to get on my Jeep SRT8. They managed to fix it, I don't remember how though.

[Neubium]

I am hopeful the O2 sensor adaptors will correct the issue. I may be in for a series of problems that will need to be resolved. I was not expecting the installation of the full flow catayltic converters to casue so many trouble codes. The full flows are not cheap. I expected the investment to provide improved performance without an engine light.

I will purchase the adaptors today. I will let you know if it works out.

[Neubium]

2010 SRT Challenger Full Flow Catalytic Converter Update: I installed full flow converters on my SRT Challenger. Immediately after installation of the full flows, I received trouble codes 420/430. I went to the Bigdaddiesgarage site and purchased two angled CEL fix adaptors ($60.00) to install with the 02 sensors. Simple installation instructions were provided with their shipping notification e-mail. When I responded to their e-mail, I included a brief summary of my particular issue. In response, I was directed to a special link on their site where the SRT/Full Flow converter issue and 420/430 trouble code was reviewed. The web link basically indicated that the SRT would require both the angled CEL fix and the CAT simulator together to prevent the codes. I then ordered two CAT O2 simulators ($100.00) to go with the two angled CEL fix. After receiving all parts, I climbed under the car to perform the installation. The passenger side was no problem. The drivers side required the full flow converter to be disconnected and dropped down to install the angled CEL fix. Once complete, I reset the codes and took it for a drive. Within 10 miles the trouble light was back on. The 420/430 code was not the initial cause of the trouble light. I received the P2036/2038 codes.

Anyone want to purchase very slightly used full flow cats and $160 worth of hardware designed to trick the computer?

I am going back to stock converters. Its just not worth the headache. Lesson learned by me.

[Mike_Levy]

P2036 DODGE - Exhaust Gas Temp Sens Circ Bank1 Sens2

P2038 - Reductant Injection Air Pressure Sensor 'A' Circuit Range/Performance

I've never even heard of a Hemi throwing those codes. They look almost like diesel codes. Very strange.....

[ricks]

I can't speak for the SMS supercharger, but the Kenne Bell website says this in it's FAQs:

"12. Our dyno tests indicated “0” HP gain with cat backs. Even removing entire cat back was “0” HP. Dodge exhaust is very efficient."

http://www.kennebell.net/KBWebsite/SC_p ... /Dodge.htm

[Mike_Levy]

Most catbacks these days are for sound only. The restriction is the manifolds on 95% of the vehicles now. The only time you're going to get a power gain from a cat-back is going from a single exhaust to a dual, and even that is going to be mostly high rpm power. Cats are iffy. Some manufacturers are using pretty high flowing cats, and for the most part they aren't worth replacing unless you have no choice, like with long tube headers.

Its important to realize, that now that everybody (except me) is looking for maximum economy, manufacturers aren't restricting stuff the way the had in the past. A free flowing engine is an efficient engine, and efficency maximizes economy.

[Neubium]

The issue was not an insallation of a cat-back exhaust. I replaced the catalytic converters with a full flow version. The car already includes a modified, high performance exhaust, and the resonators were eliminated. I did observe in a short period of time that the MPG did go up a little with the full flow catalytic converters.

I am going back to the stock catalytic converters. For me, the full flows just are not worth the hassle. I removed the stock cats and installed the full flows because I misunderstood some information regarding the custom tune that is presently on the car. I believed that the custom tune was developed with the full flows installed. It makes sense to me to have full flow converters with the SMS supercharger. Anyway, I was wrong! After I started having these issues, I contacted the SMS installer to clarify. What I discovered is that it took a month to get this particular custom tune just right. I also learned that the full flow cats did create a challenge during the fine tuning. The tune was just never quite perfected with the full flows. I was basically advised to put the stock cats back on and to not modify the custom tune in an attempt to compensate for the full flows. The programmer explained that the tune on the car, with the stock cats, SMS supercharger is perfect. This is the real reason the full flows were in the trunk when I received the vehicle.

The hardware from bigdaddies.com did as they advertised and prevented the 420/430 codes. I was nieve to think it would take care of all codes received.

Lesson learned.