Prelude keeps turning off

[Arm&hammer]

I have a 1998 honda prelude.
Every time i rev the car up and let the rpms go back down the car either shuts off or rpms go really really low and it almost turns off.
It also does it while i'm driving.
It doesn't do it as much when the car is at normal operating temp but when its cold it does it alot.
I think the cat could be clogged up but i have no clue.

[preferredduck]

cat is clogged or it may have a fast idle thermo valve which is what keeps it idling at low temp, when it warms up the idle air control valve takes over. you may need to adjust the idle screw or even the timing could be off.

[Arm&hammer]

thanks for the info. I gutted the cat and it still had the same problem but it ran a lot better. I'm gonna clean the throttle body and fitv and see if it runs better.

[preferredduck]

also has the throttle body ever been off, im asking because i had someone make a home made gasket for mine and for 2 years the car would shut off even going 70 down 85 and it turns out the MAP sensor hole was blocked some or all the way. if carbon or dirt has blocked it this can cause that too. it took me a long time to find mine. keep us posted.

[Arm&hammer]

alright thanks man. Its pretty sure its a problem with the throttle body so i'm going to clean it out and mess around with it tomorrow. I'll let you know what happens.

[Arm&hammer]

I was wondering if the ignition or main relay could possible be the problem. I cleaned the throttle body and fitv and it still keeps turning off.

[folglalb]

+1 on the ignition. You could check the main relay, but it sounds almost 97% like the ignition, just had this same problem with a 91 Escort Wagon. snagged it up for $100, changed the starter, solenoid and igntion. works good as new. But anywho, it ended up being the ignition.

[Theycall_Metue]

i dont see how the ignition would cause the problem, it would cause problem with starting the car,not idling
check for vacuum leak, could be one of the problem

[Arm&hammer]

I cleaned the throttle body and it helped a lot, but it's not really an idleing problem the car idles fine it just turns off while driving so i think its the main relay. the part is only 20 bucks on ebay so i might as well try it.