I have searched but I don't think anyone ever posted a fix for this problem. In town driving no problems, after 10 to 20 mile interstate driving CEL comes on, 1 blink (O2 sensor). O2 sensor in exhaust manifold replaced with a new Bosch sensor, reset ecu, same thing. Changed spark plugs, reset ecu, same thing. Tried different ecu, same thing. Gas mileage slightly less than DPFI, not much so I don't think it is running rich (I don't smell gas at the exhaust either). The car runs better with MPFI but the CEL is bugging me. The CEL goes away when I turn off the ignition and stays off until I get back on the interstate again (42 mile one-way commute to work). Some of the archives have brought up catalytic converter, timing advance and retard, fuel pressure, and wiring. Has anyone found the cure.

'90 CRX DX D15b2 With a MPFI swap, PM6 ecu, brand new Distributor King TD-02XP distributor.

 

I got me the same problem so any help would be great

 

Bump for an answer

 

Check your cap and rotor, spark plug wires , and if those or ok check the ignition coil. When they are craked this happens in EF cars. maybe it was bad when you got the distributor.

 

I will try that this weekend. Any other suggestions for me to try?

 

Still looking for the cure to this problem. The archives had other posts with this issue but has anybody nailed this down.

 

its funny i was reading this thread right b4 i put a 91 ls motor into my 91 dx civic, and i was hoping that this wasnt goin to happen..but sure as **** i got a code 1 also..now correct me if im wrong but isnt a code 1 o2 sensor..or reisitance within the harness..similiar to code 34 which is fuel supply something..anyhow..rustbucket did you soder the whole harness?...or just butt connect everything?

 

I've never had good luck with Bosch parts, plus just cause it's new doesn't make it good

 

All connections are soldered. I'm not measuring any resistance from the ecu plug to the O2 sensor plug so I don't think it's a wiring issue(but I have been wrong before). The sensor that had been on the car since I got it last year(never gave a code at all)was the first to give me that code so I bought a Bosch and it gave the same code under the same conditions as the other one. So I think it has something to do with my MPFI swap, because that is when it started. I think I have some kind of tuning issue. If the O2 sensor is giving me a code, is it because of running rich or running lean. What other issues make an O2 sensor give a code? Once the ecu is alerted of a problem, what does it do?

 

What does the ecu do when it gets a code 1? What will make it give a code 1? Maybe I can check from this angle.

 

Try another ecu and see if it goes away

Is the ecu chipped? I use to run a pm6 with turboedit and like twice a day the o2 cel came up. I think it was a programming error. Since then i have gone obd1 with wideband as my o2 input

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boosted Chemist &raquo;</TD></TR><TR><TD CLASS="quote">Try another ecu and see if it goes away

Is the ecu chipped? I use to run a pm6 with turboedit and like twice a day the o2 cel came up. I think it was a programming error. Since then i have gone obd1 with wideband as my o2 input</TD></TR></TABLE>

its crazy b/c the civic i have i drove for like a week and the integra i pulled the motor from i drove to my shop no CELs at all..i had to have fucked something up in the harness but i dunno what..everything is sodered 100%..im lost with this one..i may just do the obd1 conversion.

 

Do you notice if the CEL pops on when you are on or off the throttle? I am having the same issue but the code only pops when I am off the throttle completely.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jasond &raquo;</TD></TR><TR><TD CLASS="quote">Do you notice if the CEL pops on when you are on or off the throttle? I am having the same issue but the code only pops when I am off the throttle completely.</TD></TR></TABLE>

That was what happened with me, as i let it the car slow its self down it would pop on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jasond &raquo;</TD></TR><TR><TD CLASS="quote">Do you notice if the CEL pops on when you are on or off the throttle? I am having the same issue but the code only pops when I am off the throttle completely.</TD></TR></TABLE>

nah its on all the time...did u swap the outer tps wires?..

 

I had rywire do my conversion so I am confident that isn't the problem. But this isn't my thread and the problem doesn't bother me that much.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jasond &raquo;</TD></TR><TR><TD CLASS="quote">I had rywire do my conversion so I am confident that isn't the problem. But this isn't my thread and the problem doesn't bother me that much.</TD></TR></TABLE>

hmmm well if you have the same CEL then your car is running in open loop and you could also be loosing power?...

i maybe wrong.

i know one of the honda-tech gods have an answer.

 

Do you have any exhaust leaks? I had a 92 accord that threw the o2 code because there was a leak in the flex pipe. I went through 3 o2's before I figured it out. Otherwise I sounds like a wiring issue

 

1 wire o2 needs to trace to c16 at the ecu, next check sensor itself, then try new ecu... FYI, o2 sensor error code wont make car slower, under WOT ecu wont correct A/F... Basically under WOT o2 is not used

-Ryan

 

OK let me see if I can answer all of these posts(Thank you for all of them).The CEL pops at around 3000-3500 rpms, not WOT or letting off throttle. I have tried another ecu(neither one of them are chipped). I have checked and moved my ground wires. I have reset the ecu each time I checked or changed anything. I have checked continuity from ecu plug C16 to sensor plug. The exhuast is old, maybe stock, so I will check that. The harness was bought(sorry Ryan, it's not Rywire, I could not send my stock harness at the time) but I believe the TPS is wired correctly. I have another O2 sensor I will try this weekend, but I still think this is a tuning problem since this code 1 did not happen before the DPFI-MPFI swap.

Can anybody list what the O2 sensor is looking for, and what the ecu does with the information it gets from the sensor when it is reading correctly, when it gets the error code, and what it does in an open loop situation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by droppedcrxsi &raquo;</TD></TR><TR><TD CLASS="quote">1 wire o2 needs to trace to c16 at the ecu, next check sensor itself, then try new ecu... FYI, o2 sensor error code wont make car slower, under WOT ecu wont correct A/F... Basically under WOT o2 is not used

-Ryan</TD></TR></TABLE>

have you seen this problem b4?

 

get an honda o2 the bocsh are too slow

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SFlCrx &raquo;</TD></TR><TR><TD CLASS="quote">get an honda o2 the bocsh are too slow</TD></TR></TABLE>

already did that.

and your sig was my old life...except I worked for acura

 

Bumping to keep this active.

 

Still looking.
.

Can anybody list what the O2 sensor is looking for, and what the ecu does with the information it gets from the sensor when it is reading correctly, when it gets the error code, and what it does in an open loop situation.[/QUOTE]