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Bad Factory Cat?

Posted: March 24th, 2009, 11:11 pm
by Heck
To make a long story long:
My cat was plugged badly, and from all indications, had been for a long time. I think it was partially plugged from the factory (Rubicon ordered in Dec. '02). Brand new, the power just died above about 4000 rpm, and I averaged 14.3 mpg, with the stock 31" MTR's.
Now I've got a 2" lift and 32" tires, and a stroker, and after rodding out the cat, I'm averaging 16.2 with my foot in the floor. The stroker is the animal I had always hoped, running strong past 4500.
Have any of y'all seen this with your own rig?

Re: Bad Factory Cat?

Posted: March 25th, 2009, 5:33 am
by Mgardiner1
no, but i'm jealous, cause i've got a 4" lift and 33s, i can't get better then 13 mpg when i'm pussy-footing it....

Re: Bad Factory Cat?

Posted: March 25th, 2009, 6:10 am
by dwg86
Hey Mike, what gears are you running?

Re: Bad Factory Cat?

Posted: March 25th, 2009, 6:43 am
by yuppiexj
dwg86 wrote:Hey Mike, what gears are you running?
When I was running 32s on 3.55s in my 3/5" lifted XJ I got 13-14mpg.
I swapped in 4.56s and got 19.5-20 mixed and 22 highway.
That was on a stock 4.0 renix with 150K miles, my home built front bumper weighed in at ~200lbs.
I did have the correct speedo gear for both setups.

Passing power was much better, it rarely shifted down at 60+, very light throttle was required to reasonably accelerate or maintain any speed.

Not meant to be a hijack just possibly helpful info.

Re: Bad Factory Cat?

Posted: March 25th, 2009, 6:58 am
by dwg86
Yes, was helpful...thanks

Re: Bad Factory Cat?

Posted: March 25th, 2009, 5:23 pm
by Mgardiner1
4.10 gear ratio w/33" tires. I think i'd be better off with 4.56's but i just built this ford 8.8 and am not gonna dump money into another gear set now.