Let's say some thug cuts off 1 of the 2 catalytic converters you have on your truck.
Instead of replacing the converter you just add a straight pipe.

Running the truck afterwards, check engine light is on and the code you get is basically for a faulty convert/no converter. When I asked others about this scenario, I have been told:

- The engine will continue to run just fine. But you'll have the check engine light to deal with come inspection time.

- The engine will run a little leaner. Fuel mileage will drop but nothing really noticeable.

So what's the bottom line as far as how your engine is going to run, what to expect, Good/Bad to do, not good long term, converts are just a B.S. emissions part and not needed, etc.? Your thoughts?

Engine will be fine, but you will have the check engine light.

Like Redchevy said...Engine will run fine, check engine light will be on, BUT it will not pass a state inspection!

Not sure if no cats will affect the back pressure. If it does you might lose a little low end torque.

Just complete the bypass and get a tuner to adjust around the bypass. It�ll run better.

Thought about that as well.



OK, sounds like all should be fine.
Thanks

the front o2 sensor monitors exhaust gases out of the engine for lean or rich conditions, the rear o2 sensor monitors emissions out of the cat. so fuel mileage, so to speak, will be from the front o2. so no tuning or tuner needed

If it was stolen by some low-life thieving scum Then call police and get a report, turn it into your insurance and then have it replaced at the dealership. You're out the deductible but you wont have to worry about inspection issues, warranty issues (if still under warranty) or depreciated value when you decide to sell it or trade it in. Tampering with the emissions system by trying to bypass it or fool the ECM/ECU may come back to bite you in the future.

You a breaking the law anytime you change are tamper with the emission system.A lot of the guys running coal burners are tampering with there emission systems. Will cost them when they get caught.

Another solution, you could move to Alabama which doesn't do state inspections!

What vehicle is this .... most don't know the cat has been gutted/removed unless the o2 sensor is throwing the code.

What I am getting at is that somebody with HP Tuners or EFI Live can turn it off and even tune for better performance and mileage.

Have any of you done business with a Colby Lehman?

Look up " exhaust test pipe", then get a tuner to do the work around, or not. If flanged and bolted in, you can even swap them out come emission time and have the best of both worlds.