Nick97hatch

97 HB D16Y7 I/H/E and no cat.

Ever since I put on my new header I've been throwing CEL code 1, and the engine stumbles if I am below 2000 rpm for too long. I am wondering if I am not creating enough backpressure for the O2 sensors to read properly. Hence being above 2000 rpm creates the proper amount of backpressure.

The wiring to my O2 sensor is correct. It is factory wiring. I find it hard to believe that my sensor is gone bad seeing as how it was fine before I installed a new header.

Header is 4-2-1, staight pipe all the way to the "race" muffler.

Nick

civictildeath

exhaust work usually kicks the o2 sensors.

if you put a cat and/or a resonator on there it shoud cure the stumbling problem if it is not caused by the o2 sensor not working.

phasewest

sounds like the O2 sensors are throwing codes on you. Probably the second one since it won't be reading any different than the primary one. The ECU is most likely throwing a P0420, Catalytic converter failure or something. As for the stumbling engine, I'm not too sure. You could check to see if it's backpressure, but I doubt it. Stuff the resonator in the muffler and see. How long will it idle before it starts to stumble?

menkio

might be a dumb question.. but did you plug in the secondary o2 sensor.. sounds like the ecu is in safe mode.

Nick97hatch

OK I'm kinda confused bare with me.

The code is either P0131 or P0132, code 1 is either of the two. The primary sensor low or high voltage. (according to the flashing cel) If this is the case then the sensor is prolly just gone kabluie.
If it is actually the secondary sensor after the cat messing with my ecu then....
*Do I NEED to have a cat?
*Can I rewire something to trick the ECU? (will that hurt my motor?)
*If I need to put a high flow cat in the secondary must be moved to behind the cat?

Also what is and how do I turn off "Safe mode."

thanks
Nick

phasewest

you said it was a 97 right? cuz the flashing on an OBD2 car doesn't usually mean anything. You have to have a code reader to download the codes from the ECU. OBD2 is anything 96 and newer. My question is are you trying to interpret the flashing? Secondly, in response to your query...

1. I would say that you should have a cat
2. I'm not sure you should try to trick the ECU at this stage.
3. Yes, The second O2 sensor goes behind the cat.

(edit) like I said, if you have the code read it should come out as P0420 Catalyst System Efficiency Below Threshold



Modified by phasewest at 4:03 AM 2/10/2005

pdiggitydogg

flashing cel doesnt mean anything? WTF are you talking about? You can pull codes just as easily as obd1!

Code 1 is primary o2, yes. Do you have the o2 sensor connected and in the header?
Yes, you NEED a cat. It is illegal not to and you will throw codes for 2ndary o2 w/o one.
You CANNOT fool the ecu for primary o2 sensors...you need that ****.

You turn off safe mode/limp mode by fixing the problem and THEN resetting the ecu

Nick97hatch

Yes the Primary is connected. The secondary is also connected. Although with no cat I have yet to throw a code for the secondary 02 sensor.

Will a High flow cat get rid of this damn raspyness that developed from removing cat?. Cause I have one, but I looked through it and thought WTF? It is staight through so I couln't imagine it actually cleaning up my exsaust any.

Thanks
Nick

p.s. Can I still drive to work and back until the weekend? Or will this cause alot more problems?