Bypass pipes installed! Now a problem?

[JAAY]

BYPASS Pipes = you just bypassed your secondary catalytics and now your 02 sensors know it and are throwing the code. You can buy 02 extenders or have the ecu reflashed with a ROW flash.

I hope this helps.

Jay

[ddb]

Originally Posted by JAAY

BYPASS Pipes = you just bypassed your secondary catalytics and now your 02 sensors know it and are throwing the code.

Jay

Jay,

How do the O2 sensors/DME detect this downstream change?


Thanks,

ddb

[JAAY]

The dme detects that there gone by reading the difference from the first set of o2s to the second set. The first set was pre cat and the second set is post cat.

[Allen K. Littlefield]

Originally Posted by JAAY

The dme detects that there gone by reading the difference from the first set of o2s to the second set. The first set was pre cat and the second set is post cat.

Interesting. When I installed my secondary cat delete pipes I have had no issues with CE lights. There is a O2 sensor fore and immediately aft of my primary cat. There are NO sensors around the secondary. I have passed NYS emissions with no problems for two years now and have never had a CE light come on. I have an '02 2.7 model. Keep us posted on what you find that is triggering the light.

AKL

[tamarsha]

AndyA6... you have the bypass pipes on an '04 right? The o2 sensors are on the primary cats. Adding the bypass (secondary cat delete) pipes does not effect the operation of the o2 sensors. Go by a cheap, $50 code scanner and see what comes up. I always clear the code and ignore it the first time. If it comes back, then I will see about doing something. Actually, I have cleared a code for an “aging o2 sensor” about 5 times now. I probably should do something about it.
Todd

[JAAY]

Ahhhhh. Didn't realize you had a newer box. There correct. It should not affect you. Nmay e time for new sensors or and a maf

[Cloudsurfer]

Originally Posted by JAAY

BYPASS Pipes = you just bypassed your secondary catalytics and now your 02 sensors know it and are throwing the code. You can buy 02 extenders or have the ecu reflashed with a ROW flash.

I hope this helps.

Jay

Ummm no. The pre-cat O2s are in the headers, as are the post-cat O2s. The secondary cats have no O2s behind them.

There is absolutely no reason you should throw a CEL from removing the secondary cars.

[JAAY]

Hey cloudsurfer. Ummmm Read all the posts!

[AndyA6]

OK, scanned the car over lunch break at Autozone.

All 4 Oxygene sensors show a code...... cleared/erased. After 2 miles check engine light back on.

Hmmm, unusual to have all 4 sensors show a code?!?

Any ideas?

Thanks!

[DenverSteve]

It's interesting when these threads just stop. Did you find the problem? What was the fix? I'm going to change my exhaust also and agree that your exhaust change alone shouldn't cause the stated problem.

[jmatta]

I deleted the secondary cats years ago and have never had a CEL...something else is the problem.

I know this is an old thread, but perhaps the info will help someone else.

[paulv]

Originally Posted by DenverSteve

It's interesting when these threads just stop. Did you find the problem? What was the fix? I'm going to change my exhaust also and agree that your exhaust change alone shouldn't cause the stated problem.

DS,

Agree, it would be nice when people find solutions to post the results so others can benefit.

Another pet peeve I have when people say that the DME set some codes and never state what the codes are. On AndyA6's last post, codes can be set for all O2 sensors depending on the problem and DME version although only one O2 sensor could be the problem.

Regards,
paul...

[AndyA6]

Originally Posted by paulv

DS,

Agree, it would be nice when people find solutions to post the results so others can benefit.

Another pet peeve I have when people say that the DME set some codes and never state what the codes are. On AndyA6's last post, codes can be set for all O2 sensors depending on the problem and DME version although only one O2 sensor could be the problem.

Regards,
paul...

Steve/Paul, I agree! Sorry it took me so long. First of all I finally bought a Durametric cable, an extra laptop and started scanning.

Here are the codes:-

P0036:
Porsche fault code 373 - Oxygen sensor heater behind cat. conv. bank 1
P0056:
Porsche fault code 374 - Oxygen sensor heater behind cat. conv. bank 2
P0141:
Porsche fault code 14 - Oxygen sensor heater behind cat. conv. bank 1
P0161:
Porsche fault code 4 - Oxygen sensor heater behind cat. conv. bank 2


After erasing the codes come back almost immediately.

One theory is that during the pipe install some wiring came loose? I believe that is almost impossible, I watched/helped to do the install.

I also had no chance to get under the car, I totally injured my back and could hardly wallk for the past 2 weeks....... just getting back onto my feet! That did not prevent me to install my 997 shifter, trust me, can be done sitting down

However, I just now scanned again, same codes, same CL coming back after a couple of miles.

Well, there you go!

Later,
Andy