Engine Code CEL 1 hlep! Video

[ac011]

91 NSX with comptech headers. Just installed both Denso o2 sensors and CEL light on after 20min of driving. It will turn off after I restart the car but on again after 20min. I pull the code and it looks like CEL 1? I thought the front sensor was defective so I replace a new one but some CEL code again..

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[Larry Bastanza]

1. Are you 100% sure the replacements are the correct type?

2. Time to check the wiring/connectors

Regards,
LarryB

 

[pgilliam1]

Looks like Code 1 to me too (bad primary O2 sensor).
Have you reset the ECU (pull the clock fuse in the front/under hood fuse panel)?
Was the car running poorly before you changed the O2 sensor?

 

[ac011]

I already replace the O2 sensors once 2 years ago with NTK. The car start running poorly last month and received CEL 44. I thought the NTK were bad so, I replace some Denso this time.

Part #234-4093 and 234-4096

http://oxygensensors.com/catalog.php?&pkey=1000843

I reset the ECU by disconnect the battery. I ran the car hot for 20min and got CEL 1 this time?? Check all the wiring and connectors and they are all good....

I have no idea what to do now... Should I replace it again with NTK and see if the CEL will go away? or problem with ECU??

 

[AdvansCPAP]

It's possible the wiring might be intermittently touching the header if you didn't tie it down good. Once the wire melts and touches the hot header, a check engine light will show up.

 

[pgilliam1]

So is the engine running OK?

These type connectors are known to have problems (the small size of the pins and their receptors can cause opens).

If the code appeared just after replacing the sensor, it's either the sensor or the connector.

I haven't heard of any ECU failures with these cars but it could happen (it would be my last guess).

Do you notice any difference in the exhaust outlets (smell, temp, sound, etc.)?

Since you received a code 44 (which is a rear bank fuel code) and have a code 1 (which is a front bank low voltage O2 code) the codes don't match up so it doesn't help much .

 

[ac011]

I already check all the wires. They seem to be good. The car running fine so far with the new sensors, only problem is cel code after engine got hot. I will double check the header o2 sensors extension tomorrow.

I want to make sure the front sensor mean the one close to the rear bumper?