2012 Dodge Challenger R/T 5.7 Stage 2 MDS delete

[Merrick]

Hello, I seem to be stuck in a never-ending cycle of issues with my Challenger. I will give a chronological breakdown to give an idea what I am now dealing with. I initially experienced lifter collapse and with MDS lifters, and a camshaft that looked like it went through a wood-chipper. We decided to do a MDS delete and upgrade the camshaft to a Comp Cam Stage CK201-303-17 to try to build better than it was. As a disclaimer I am not a very mechanical person, I researched a lot and with the help of my cousin we pieced this thing together. We bought the full cam kit from High Horse Performance and did the swap. Then learned the hard way that the car would not run without a custom tune, I purchased the DiabloSport I3 and found out I was out of my depth. I had a tuner install a custom tune, and got it running with this cam.

About a week into driving my resurrected car it started running terrible, took it back to the tuner and found out my intake was internally damaged and I had a massive vacuum leak. The car sat for 8 months until I could source an intake and we put it in, once again back up and running in 2024. A week goes by, car is running like hell, I smell nothing but gas. I figured out my oil is full of gas, exhaust pipes are covered in black soot. Straight forward seems like the car is running way too rich and dumping fuel/flooding. My fuel trims are short term 0-6%, long term 6% steady, Which my tuner said is perfectly in range. With my I3 I can see O2 body 1 and 2 are coming back with a 299.2% reading. My cousin pinched one of the o2 sensor wires in the valve cover during the rebuild. I'm going to swap that one but somehow I still wonder if my tune is off. I was both wondering if anyone here could offer any advice and also if any of you do custom tunes for the Diablo I3?

[Lucas57]

Of course get the O2 sensor fixed first, but I am having a good experience with Johan at Diablotoona. He is tuning my car for a cam remotely by emailing him log files from the I3. So far he’s been great and super fast response time. Reach out to him via the Diablotoona website.

[mikel]

My first thought is that the intake may have been cracked/leaking slightly when it was initially tuned, and the issue was 'tuned around' at the time. Once you fixed the intake, assuming its all good, it may have thrown off the fueling as it was skewed for the damaged manifold. Also, any O2 sensor issues will cause fueling and drivability issues, so for sure fix that before you do anything else.

You are in good hands with Johan