Noise

Okay guys, I have a factory deck in my 2001 Jeep Grand Cherokee and the Memphis 4 channel and 500d for the subs.  When I had an aftermarket deck in, everything was fine.  Put factory deck using stinger hi level convertor to the Memphis XO-3 3 way signal processor.  This piece gives me front/rear+sub output to my amps with only 1 hi level. 

The problem is that I have a lot of horrible engine sound thru the speakers, with a loud pop out of my sub when the car is turned off.  I used the power/ground/remote off my factory deck wires to power the signal processor.  I know it is not with the RCA's or the amps, as it worked fine with an aftermarket deck.  Could it be the processor or the hi-level convertor?  I have also checked the gains on all my amps with the engine not running and everything sounded fine, but with the car running it sounds like a fast and furious race!!  Please let me know something guys.  Thanks a ton.