Please help (Hemi related)

[bee0912]

I have at least 5 personal friends with the same truck with allot more mods ( heads, long tubes, cut outs, cam, intake, etc...) than this. And they do not have this problem. I am going to have them visit this thread and see if they can shed some light on this.

That would be great but i also know people with big cams and heads with no problems so i really dont know at this point

but like i said im going to talk with this company and see what they can do for me

 

[FSTJACK]

Anytime you detonate/explode a muffler like you have it is beacuse it has a mixture of raw fuel and air/oxygen in it, along with an ignition misfire.

The muffler will be destroyed inside if it is split at the seam, replace it.

It certainly sounds like you might have an exhaust leak causing "false air" to enter the exhaust system confusing the O2 sensors. The exhaust system needs to be "tight" allowing no outside air to enter before the O2 sensors. There can be no exhaust leaks for the system to function properly.

The brand and type of fuel used can also cause or contribute to problems such as yours. Low grade fuel (some off brands) and some majors have a great deal of alcohol in it causing a lean condition. Some states have switched over to Winter gas which is also highly oxygenated and will cause a lean condition. This combined with other things (or sometimes by itself) can really cause driveability and running problems.

I would replace all the plugs and check the integrity and function of the plug wires. Then remove and test the O2 sensors one at a time, replacing any that have slow response time.

 

[mopower1958]

Everything Jack said plus,If you have a continuos lean O2 sensor, you may have a vacuum leak. Check the integrity of the pcv valve and related plumbing, and any other hose connections at the intake. With it idling take some air intake cleaner and spray around the throttle body gasket and along the cylinder heads where the intake bolts to it. If the engine idles up at any time you are spraying check that area for a leak. An exhaust leak will cause a backfire as will a misfiring cylinder. The combination of a misfire (rich exhaust) with an exhaust leak (ingested oxygen) will cause a backfire as the added air ignites the rich mixture in the hot exhaust.

 

[TNVIPER]

For the next 24 hours, there is no God in Columbus, OH.
Only Tressel.


We picked up Keith's truck at the dealership tonight. Very nice place, and some very cool service guys. When I explained the Magnaflow leak, the tech said, "Ahhh...the seam on the side. I was looking on the top and bottom.".

It seems as though Keith has done just enough upgrades on his RumbleBee to piss off the PCM. It's now time to feed it.

The CAI is letting in plenty of air.
The headers and catback are letting out plenty of air.
Now he needs enough fuel to keep the engine running.
The stock PCM is at it's limit regarding fuel delivery.

He's got some info on new PCMs and tuners. Hopefully Santa comes a bit early and gives him some gas.

I know a lot of people with the same mods on hemis and they have no problems.....my brother has a RT Charger with a CAI, headers, hiflow cats, Magnaflow catbacks and ported heads...with no modifications to the PCM it showed an WOT A/F of 12.8......

He should check for exhaust leaks and vacuum leaks....also make sure the O2 sensors were not damaged.......when I first installed my exhaust and Roe SC I had trouble running way rich (below 10 and off the scale)...it finally came down to the left O2 sensor had been sodered to repair a wire...most likey the shop that installed the Magnaflows did this. New O2 sensor and A/F jumped to 11.6 at WOT....about right for a FI engine..

Also check the ATI sensor on the CAI for damage..

 

[bee0912]

I know a lot of people with the same mods on hemis and they have no problems.....my brother has a RT Charger with a CAI, headers, hiflow cats, Magnaflow catbacks and ported heads...with no modifications to the PCM it showed an WOT A/F of 12.8......

He should check for exhaust leaks and vacuum leaks....also make sure the O2 sensors were not damaged.......when I first installed my exhaust and Roe SC I had trouble running way rich (below 10 and off the scale)...it finally came down to the left O2 sensor had been sodered to repair a wire...most likey the shop that installed the Magnaflows did this. New O2 sensor and A/F jumped to 11.6 at WOT....about right for a FI engine..

Also check the ATI sensor on the CAI for damage..

All mods listed were done over a year ago no problems from install