What is wrong with my engine?
 

D17a2

1 O2 simulator connected to ECU.

Engine will not pass 4k RPM. I have to shift right before 4k RPM. If I try to keep going, the engine "quits" or "boggs down". Almost like it is giving up.

Is it the ECU, O2 sim, or internal problem?

The engine light comes on and off. When it is off i can go past 4k RPM.

This leads me to think the O2 sim is failing.

Opinions? Please...

Thank you,

Christopher

Re: What is wrong with my engine?
 

It's the O2 simulator throwing your car into limp mode which is why you can't go over 4K on the tach. Remove it use a spark plug defouler to fool your ECU into thinking you have a cat.

Re: What is wrong with my engine?
 

i think its a different problem. even with me running no o2 sim or defouler and the ecu knowing my car has no cat it still runs fine. when the CEL is flashing it usually means your engine is misfiring big time.

was it running fine before and this just happened randomly? or did you install it and its doing this now? if it just happened after the install it could be the o2 sim. check your vtec wiring first and maybe clean out your vtec solenoid screen. thats an easy way for the car to throw limp mode. same thing happened to my car and it ended up being my vtec screen.

Re: What is wrong with my engine?
 

It may not be the O2 coz when i have my civic i have no cat too....coz the ecu already know u r running without a cat so the CEL will be on...use obd and it will show u wht's wrong with ur car or the motor...

Re: What is wrong with my engine?
 

did you get a code when the light came on?

Re: What is wrong with my engine?
 

Pull the code... There will probably be a stored code even when the CEL is off in your case so if you get the code you will know the issue.

Re: What is wrong with my engine?
 

I have not taken it in to check for a code.

Thanks for the input guys, the O2 sim was working fine for months before this randomly happened. Today the engine light went off and on again after an hour of driving.

Guess I have to check for a code and take it from there. 95,000 miles under her belt. ya-yuh.

Re: What is wrong with my engine?
 

Its a D17, theres your problem.....

but really it could be your VTEC sylenoid too. I had the same issue and thats what it turned out to be. A 02 sensor wont make your car go limp. I ran with my CEL on for months before putting a defoiler on it.

In fact your problem sounds exactly like my problem and at the same RPM.

Re: What is wrong with my engine?
 

good to know, it does sound like i might need to clean it up. Recently for the past 2 days, it has been running fine with no cut off.

so im scratching my head on this one.