I made the jump today and had my cats changed and wow what difference in sound. I was thinking of changing my exhaust again but not after changing the cats nicer tone to my magnaflo.

 

smkeater did you go ahead and use magnaflow hi flow cats? im going to be replacing my 4 with 2 real soon as well.

 

Yes magnaflow hi flow cats so far no problems or power loss

 

do you remember your part number? hearing your results makes me want to get mine done NOW!

 

You are wasting your money. They don't contribute to A/F's in any way whatsoever. So why would you go spend $120+ to change them?

 

What is the 5F capacitor for?

 

its hooked up to both my amps. its probably a little over kill but both my amps combined im pushing around 2100 watts rms.

 

Chester, what do you mean with A/F's? I couldn't find a standard for that and I don't want to guess. Let me know so I can stay on the same thought. As for the sensors I am not planning to pay $120.00 for them. I purchased a pair of Motorcraft sensors in Ebay for much less than half that amount. After 113K miles fresh sensors will help with a better running engine.

 

I was talking about the air/fuel ratio calibration. The front set of O2 sensors monitor engine performance, and provide information to the computer that helps it calibrate how much fuel to inject for best performance and economy. The rear O2 sensors monitor catalytic converter efficiency. They essentially just sit there and watch the catalytic converters, and they tell the computer if there's a problem. So, there's no diminishing efficiency with the rear O2 sensors. They either work, or they don't. There's no middle ground. So, If you don't have a check engine light caused by a bad O2 sensor, then there's no point in changing them.

The debate, however, comes with changing the front set of O2 sensors, since they monitor engine performance, some people think that they might get worn out over time. I talked to a mechanic at the dealership, and he did not recommend that I change mine until I have a problem. He told me that I would be wasting my money. But I changed them anyway, hoping to get better gas mileage. I didn't. And if mine aren't worn out after 160,000 miles of hauling wheat, cotton, bulldozers, welders, peanuts, equipment, etc, then nobody's are.

So, I would say, just wait until they quit working, then change them. But regardless as to whether or not you do, it is totally rediculous to change the rear O2's unless they give you problems. And even then, fixing them will not change any aspect of the operation of the vehicle, except, remove the check engine light.