Code 1 O2 sensor error lights up while open loop

see2k · Post by **see2k** » Tue Apr 01, 2003 7:45 pm

Well this has happend to me once but its happening to my friend alot.

On occasion his check engine light pops up with the CEL Code 1 Primary O2 sensor. I find this hard to believe when his car is running in open loop and therefore his O2 sensors are not functioning, or the readings are being ignored.

To humour the error we did replace the O2 sensor, but found that not to be the problem? Could this be an ECU issue? Its a p72, and my p28 also did that code once, but never came up again after I shut down and restarted the car.

We're going to check whether the rom needs updating, however, if that is not the problem, what else could it be?

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Tue Apr 01, 2003 11:20 pm

Yup. I talked to matt about it already. They are fixin it. But it not performance related so no issues there except for the annoying CEL.

Post by **Hondata** » Thu Apr 03, 2003 9:57 am

This was fixed in RomEditor V3.2.2 It only occured once after a cold start.

see2k · Post by **see2k** » Thu Apr 03, 2003 10:29 am

Hondata wrote:This was fixed in RomEditor V3.2.2 It only occured once after a cold start.

welp it still does it.. im running romeditor 3.2.2.4 and the o2 primary sensor pops up. It usually pops up after about 50+ miles of driving and or 40 minutes.

Its consistent as to when it just pops up.. And no its not the shift light

the only other thing I can think of is that the p72 ecu is bad, or going bad, and just throwing this code out there? or there is obviously a flaw still somewhere running around. This has happened once with a p28 ecu running 3.2.2.2. After a long drive of 50+ minutes, the cel 1 pops up while I was cooling down the motor.

It hasn't happend to me ever again. but it happens to my friend consistently who i've updated his rom to 3.2.2.4

gosh i need to find my CD and reload the old version of romeditor, something like 3.1.x.x

JT · Post by JT » Fri Apr 04, 2003 11:38 pm

The same thing happened to me twice today during street tuning for approx. 10 miles. The engine is fully warmed up (water temp @ 190F). I'm using V3.22 and P28.

blkcrx · Post by **blkcrx** » Sat May 10, 2003 3:19 am

Well yeah i get this error all the time....also with a p28 and version 3.4 it seems to occur when I?m off throttle a fair bit ie city driving in traffic.. driving without driving hard. but it only happens after 20min+ of driving.
Regards James

AndyE · Post by **AndyE** » Tue May 13, 2003 5:46 am

Another data point to add...I get this CEL with the v3.4 ROM under open loop operation as well.

Hondata

Code 1 O2 sensor error lights up while open loop

Code 1 O2 sensor error lights up while open loop

Code 1

Re: Code 1

im using a p28 using 3.4 and get it too..