97 LX Emissions failure - No Check Engine Light

[ebbs306]

I have a 97 LX (no VTEC) which is 100% stock. It fails NY state emissions miserably, and on top of that, it runs fine when I first start it, and then after the engine warms up it is alot more sluggish and much noiser. This leads me to believe that it is a sensor acting up when the engine conditions change. I recently changed the air filter, plugs, wires, dist cap, o2 sensors, and checked out the catalytic converter, which appears to be in good shape. The check engine light is not on. I am thinking now it is the MAP sensor, or the CKP sensor, but both are expensive. I was wondering if anybody has any idea. Thanks in advance

 

[ebbs306]

Also, the muffler, midpipe, and frontpipe are brand new, replaced in may. the manifold/converter was $500 from the dealer, soI havent replaced that unless it becomes necessary.

 

[JCV2000]

Perhaps the fault is in your fuel system? Have you looked into bad injectors, a goofy idle setting, or crappy pump or something? See if its running rich or lean, that might be usefull.

 

[gabebauman]

Try replacing the pcv valve and check the fuel injectors for gunk.

 

[CTYankeeboy]

I have had one fail emission testing with a bad O2 sensor even though there was no check engine light.

Craig

 

[civickidd99]

What about the cat? You said it gets noisy, a worn cat will cause some noise and fawk up an emissions test!

 

[ebbs306]

i looked at it, and it looked ok. being a manifold cat, all i was able to do was look inside the hole with a flashlight. it didn't look like it was jammed up or black or anything like that.

 

[9civic7]

do you have the readings from the emissions test. Im a state inspector in MA so I might be able to help.