4.2 performance mods
03-19-2016, 03:18 AM
#1
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4.2 performance mods
Anything relatively inexpensive I can do to up the horsepower, and possibly gas mileage too on my 4.2 ? Its in a shortbed 2007 2 wd with 5 speed manual. Was hoping a chip would do the trick. Im not willing to go the expense, but has anyone ever added a turbo to this engine ? I know what the turbo charged 3.5 is capable of, I can just imagine what a turbo charged 4.2 could do.
03-19-2016, 12:17 PM
#2
Senior Member
This is the Pre-1997 section - check the 2004-2008 section 
03-23-2016, 08:27 AM
#3
Moved to 2004-2008.
03-23-2016, 09:05 AM
#4
Senior Member
Start with the simple stuff before you get crazy and turbo it. New plugs, clean MAF and throttle body, new air filter. I have a ScanGuage II plugged in to the OBD II port and it tells you real time mileage and all kinds of other stuff. My 2007 4.2 with auto trans was getting horrible mileage when I first bought it. It was the fuel rail pressure sensor under the hood that was stuck so the computer was dumping more gas than needed in the engine. I was blowing black smoke out of exhaust. http://www.scangauge.com/