Yes. Your well within parameters with those.

Take the others to the scrap yard to off-set the cost - An AUTOMOTIVE scrap yard. Palladiums up higher now, but I got $160 for my 4 old ones. Another guy got $260 for his old ones - Depends on the market, but don't thorw them out there worth $$$$$$

 

thanx so much for all your help ill let you know how it goes

 

your cats dont affect the way your truck runs at all, only your forward o2 sensors monitor your exhast BEFORE the gas gets cleaned up by the cats and adjusts the air/fuel mixture the rear 2 are only monitors and have no control over the engine control, all they do is switch on the check engine light when it senses the cats are not doing their jobs

 

Which is what we already told him

 

So dramatically changing the amount of back pressure in the exhaust does not change the way a motor runs? You might want to do a little more research on that.

 

Uhh, yea - Incorrect - VERY

 

I know the general consensus on here is that high flows add power, long tubes add power, but no cats reduces power. All for the same reason.... Back pressure. Explain this to me please and Thank You

 

id be checking for leaking injectors my friend...

 

The rest of your exhaust system provides enough back pressure for scavenging unless you jumped up to 3 inch pipes from the cats back. Some back pressure is good but too much is worse than none. It is more about proper flow velocity and less about pressure.
Like dirt bike Dave said: do a little research. My point was: his lack of cats did not create his rich condition.

 

Yes,
a lot of us on here deleted the 4 stock cats and replaced with 2 high flow cats for sound and performance!
But,,that will not fix your rich condition.

Phil

 

in an earlier post i stated if you put a resonator on the pipe just in front of the muffler, that will give you enough back pressure that you wont notice a preformance difference from stalk if you cut your cats out.

 

You nailed it Norm. Back Pressure is just slang really.

If you remove the cats from a stock system, there's to much flow/velocity for the stock tune. You have great scavenging as far as that goes, but the engine IS NOT tuned to run that way and won't run correctly..

 

Shove a Potatuh up your tailpipe

 

dramitacally? do you even know how much backpressure an exhaust system should have?

 

Like there is one right answer that is universally correct for all motors and applications?

Do tell...


Little to no resistance , max flow is great for peak hp, high rpm applications. Drag racing, for example.

The narrower of an rpm range you expect to operate in, the easier it is going to be to find the best compromise between max flow and the right amount of resistance.

For street driven vehicles or any application where low end power is desired (like a pick up truck), the appropriate amount of resistance will allow for increased scaveging. Basically, some pressure downstream signals the cylinders to push the air out with more velocity. At low rpm, the increased gas velocity coming in and out of the cylinders allows more good unburned fuel and air to be sucked in to the cylinder, and it helps suck out the burned gasses more efficiently. So the right amount of resistance in the exhaust can greatly improve low rpm power over a less restrictive system.

The entire motor is a system with a lot of compromises. You enhance its capabilities in one area, you can hurt them in others.

In a carbed motor without computer controls, making a big increase or reduction in the restrictions in the exhaust system will alter the amount of fuel sucked in through the carb. So to maximize the benefit of the changes to the exhaust system, you need to optimize the intake to suit the changes.

In a computer controlled motor, if you make huge changes to the exhaust, you run the risk of falling outside the parameters of what the computer can adjust for. Instead of optimiziing the system, it may throw you into a default open loop, maximally rich setting.

Which I suspect is what is happening to the OP. He is losing low end due to less scaveging and running way too rich, and also high end power due to being too rich despite his less restrictive exhaust.