Alright, I have a problem. i have a test pipe and the o2 sensor is just sitting there breathing all the lovely fumes from the downpipe.

When I drive it normal, no problems. Or if i take it up to like 10 PSI for 2 seconds and shift, no problems. But if I take it to max boost and leave it there for like 5-6 seconds, the CEL light comes on. I think because it's reading "RICH". Then the car bogs like crazy in 1st because the ecu is making the engine run reallly rich. I reset the ECU. Works fine, then when I run it hard again, same problem. Only happens when I leave it in full boost for a while.

Anyone have any "TRIckS" to trick the 2nd O2 sensor? I tried wrapping Aluminum foil, but that thing FLIES off the o2 sensor and out of my exhaust.

Thanks.

 

i have a test pipe on since the rebuild and o2 sensor is pluged in and zippied to the shift linkage.. no check engine light yet... *crosses fingers*

 

Summit sells a secondary O2 sensor "fooler" for later model GM's.

It is a direct plug in for them, but from what I could see in the pic the connector had 4 prongs...so that means 4 wire O2 sensor the same as honda. So you could buy that and your trouble will be over after a little solder and rewiring.

Or, find some way(using radio shack parts) to feed a constant .1-.4 volts when the car is running to the O2 sensor signal wire. I assume that is prolly what the Summit gadget does.


[Modified by HXMan, 9:31 PM 9/12/2001]

 

Are U sure the problem lies with the O2 sensor?, The CEL can be caused by the map sensor reading boost instead of vacuum.

 

The "fooler" circuits actually oscillate pseudo-randomly back and forth between voltage levels. If you give it a solid voltage, it will eventually throw a code.

 

godspeed motorsports has a test pipe with a bung for the O2 sensor....apparently the bung has cat material in it so it fools the O2 sensor into thinking that you have a cat. www.godspeed-motorsports.com it has 2.5 inch flanges, perfect for turbo dp.

 

I think i'll try that method of just letting it hang loose lol....

 

All the second O2 sensor does is measure how good the cat. is working compared to the reading off of the first O2 sensor. Try splicing the wires to the second O2 sensor into the wires of the first O2 sensor.If it throws a code on you, it will just mean that the cat. isn't working good enough but wont throw you into a limp mode. It worked for me.

 

Actually for the 96 OBD2 you can leave it hanging outside of the exhaust system...just wrap it in something that will keep it warm.

 

what about converting to obd1??

 

I've found that to be the best solution

 

i wraped mine in foil paper. it works best. i have a question though.... what if the o2 sensor gets wet?? since it's only ziptied there. will it get damaged???

 

GSRacer: And who told you that trick?
EVIL

 

the O2 sensors work on heat, so as long as it's as warm as the exhaust pipe, then you shouldn't have to worry about water, it'll evaporate faster than you can say smooth.

 

Just out of curiosity since I plan on adding a test pipe to my Civic when I get the larget DP, what kind of zipties do you use to secure the O2 to the pipe? I'd assume the regualr zipties would melt right off so what are you using? I was intending on having a bung welded onto the test pipe to I could screw y O2 in place but now i'm not so sure if I should leave it outside or inside.

 

evil: your sister told me that trick!!! eh eh eh eh jk
he doesn't have a sister. Yes, people... master Evil gave me all the specs on how to do the trick.

 

vtc civic, contact godspeed motorsports...they have a test pipe with an O2 bung sticking out of the pipe to counter OBD2...check the pic at http://www.godspeed-motorsports.com under 'other parts' there is a picture of it. I believe it fits all integras and civics with 2.5" flanges, perfect for your dp.

 

smoothludey2:

It does not matter whether the second o2 sensor is in the exhaust stream, without the cat the ECU with throw a CEL. The secondary O2 sensor is used to measure how well the cat is working. You are better off with it exposed to open air, so the ECU thinks your cat is working REALLY well.

Dustin

 

I've tried the Foil method. The exhaust flow will eventually tear it apart.

 

friendly dustin,

obviously you haven't taken a look at the test pipe at godspeed motorsports, it was designed and manufactured specifically not to throw a CEL. At least for preludes, the 96 OBD2 you could run the secondary O2 sensor outside of the exhaust system. With the 97+ OBD2 it's not that easy to run a test pipe as the secondary O2 sensor is much more sensitive (to the temperature change as exhaust flows through the cat) so it can't be placed outside of the exhaust system. The godspeed test pipe has a special bung with cat material in it so the secondary O2 won't throw a CEL. That's godspeed's solution to 97+ OBD2....unfortunately, they only make it for civics and integras

 

obviously

 

I have a 99 civic ex, my secondary o2 sensor is zip tied to the shift stabilizer bar. The check engine light did come on when i did this. However, after resetting the ECU the light is off and has stayed off. I havent had any problems what so ever, and I have been running the car pretty hard now for about 2 weeks. I guess i should keep my fingers crossed.

 

It really isn't a big deal...the only problem with a CEL for your secondary O2 sensor is having to look at the damn check engine light all the time! I hate it!!!! (oh, I got code 63 and 91 right now just to let you know)

I was driving around with no O2 sensors for about 2 months...due to code 1, the primary and seconday O2 sensors are disabled by the ECU.

I got 28-32 mpg, and ran consistant 15.3-15.5's at the track(with P72 ECU). I pulled my plugs too and they were PERFECT. This is with a b16a2.

I just fixed my code 1 recently, and have not had a chance yet to see if my fuel economy is suffering....I bet fuel economy may have been sacrificed to decrease emissions....I don't know if this is possible, but 28-32 mpg seems to be very good milage for a mostly city driven b16. My original engine only got a few better MPG...and it was rated 35 city, 41 highway.

 

i had a problem with my ecu throwing a "insufficient catalyst" code. the way i fixed it is i cut the ecu "memory" wire going to the ecu. since it takes 2 seperate driving periods for the ecu to realize that there is a problem with the cat, everytime i turn the car off and on it thinks its the first time it's seeing the problem with the cat. sounds confusing, but it works.