Losing MPH

[cm581978]

Ran my car today and the DA was around 700 or so. My car was trapping 99-100 all day long, which was 4 miles slower than my best ET. Fdjizm suggested it may be a clogged cats. I know its not the tune, spark plugs or fuel filter, so what else could be slowing the car down?

 

[05moneypit]

Same track you normally run at? I've 3-4mph in the lights between tracks.

 

[cm581978]

Yes same exact change. Just the wheels are spinning in my head if I should be concerned or not.

 

[cm581978]

Spark plugs were changed about 20k miles ago, along with the fuel filter.
CAI filter was changed last week as well, but I'm going to the shop this morning to check on the cats. If it's not the cats, maybe its just high IAT's? I let my car cool down about a half hr each run and I had 12 runs yesterday. ET's were between 13.8-14.4.

 

[fdjizm]

Gotta be a cat.

 

[cm581978]

Correctumundo! The left cat is clogged, we put it on a lift and I held the rpm's at 2k, while a tech inspected the cats. Gentlemen, is it a much better idea to get slip on cats and leave the bassani x pipe, or just buy a whole new x pipe? I'm keeping the cats so that's not an option

 

[fdjizm]

http://www.ebay.com/itm/2-5-Thunder...r_Truck_Parts_Accessories&hash=item257c2643e1

2.5x13" $129.90 for 2.

 

[cm581978]

Ordered!