I have idle problems, the fact is that I took to change the engine, and I think it brings the catalytic converter, you need this for the optimal functioning of the engine?

 

You do not need it for the engine to operate correctly. On 90-'95 cars the ECU won't know. On '96-present the PCM will note via the second O2 that the catalyst is not working and will set a code such as P0420.

Psst, Year, sub model, and engine would be helpful to know if you are having engine issues.

 

the catalytic converter should not cause idle problems only, if it was clogged badly it could cause an idle problem and worse when you touch the gas. i think it is likely you need to look at other systems on the car...

 

I have a 1991 honda accord EX, but I did the swap with 96 engine, later verified that the engine was installed to add it as a given and so can help me more ... so if I notice is that the car still accelerated in 1500 when I switch it on and then down to 1000 in reverse trembles too, sometimes up and down like crazy acceleration...

 

you can test a Cat with a compression tester.. just take out the 02 sensor and thread that in its place. start the car and check the gauge.. It shouldnt build more then 1 or 2 psi gont let it get to hot tho

 

okas, i have another question, without the cat can get poor mileage?...

 

hate to rain on everyones parade...but recently Pat Goss did a segment on cats and what happens when they are removed.

seems our engines are designed to have a certain amount of backpressure to optimize exhaust gas flow. When you remove the car, you are disrupting the air flow that was designed for your engine. By removing the cat, your engine creates exhaust gas cavitation at the exhaust ports - causing heat to build up, which, in tern, damages the exhaust valves.

He went on to state that older american cars usually weren't affect by cat removal, because for almost a decade, the cat was "slapped on" after everything was designed.

After hearing his statements, a part of me wondered if Pat was part of a tree hugging conspiracy hell bent on creating mis-information. I don't know - but I do know that without a cat, you can expect to see a 5hp gain. Check with your states laws also...some states will fine you 1,000 for removing a cat from a vehicle that came factory equipped with one.