LouisvilleRex

Okay so let me start by saying that this is a reman From mazda that i had put in my 04 AT Rx-8 around 3 weeks ago. 3 days ago I go to start it and its barely starting and when it does start it runs rough like REALLY rough for about 5 seconds then shuts off had it towed to my dealership for them to be completely stumped when it passed compression with 8, 7.9,7.9 at front and 7.9,7.8,7.8 rear at 250 rpm.
I have the BHR ignition upgrade Upgraded 2kw starter a fresh engine pretty much im completely lost as to what it could be im thinking my Catalytic converter is completely clogged (this was my first car got it used with 20k miles in 2011 and never had it replaced with a midpipe) if anyone could give some guidence it would be greatly appreciated

BigCajun

iTrader: (1)

If you have the OEM cat that was on the car when the engine failed, then there's a pretty good chance that it's clogged.
Their failures from bad ignition misfires is one of the leading causes of engine failure.
You should inspect it.

Jedi54

iTrader: (7)

have them check the cat.
was the BHR ignition on the car when they swapped the motor?
only ask because they could have broken a wire or a plug when they reinstalled everything. I recently had a broken leading plug and it caused the car to idle poorly and it would stall out.