Bypass pipes installed! Now a problem? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

AndyA6 · 06-23-2011, 05:13 PM

Mods so far:-
UD pulley from RSS
Technotorque
Bypass pipes from Fabspeed

First the good news! Awesome sound and most def better performance!!!

Sound, deeper at idle and louder/meaner in the higher revs. no drone. At the same time not annoyingly loud, IMHO just right.

Power, def more. Before the mods I always felt a flatspot between 3 to 4,000 rpm. Now gone, very nice! Engine feels "lighter" if you can imagine that.

Installation was relatively easy, car on lift and the right tools did the job.

Also, wierd enough, the 3200 vibration is gone but I feel some at approximate 3500. Go figure! Somebody posted here that the 3200 vibe was gone as well after he installed the pipes.

Now a couple of points which are not so good.

First after 24 miles of driving the check engine light came on. Why?? Do I have to reset the ECU??

Have to check the exhaust alignment, I think one the pipes touches something.

Any comments and/or feedback please?

Thanks for reading!
Later,
Andy

JAAY · 06-23-2011, 06:01 PM

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 · 06-24-2011, 04:10 AM

Quote:

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 · 06-24-2011, 04:26 AM

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 · 06-24-2011, 05:00 AM

Quote:

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 · 06-24-2011, 05:05 AM

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 · 06-24-2011, 05:16 AM

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 · 06-24-2011, 04:51 PM

Quote:

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 · 06-24-2011, 05:19 PM

Hey cloudsurfer. Ummmm Read all the posts!

AndyA6 · 06-27-2011, 10:36 AM

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 · 09-22-2011, 08:31 PM

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.

ddb · 06-24-2011, 05:25 AM

Quote:

Originally Posted by AndyA6

Mods so far:-
UD pulley from RSS
Technotorque
Bypass pipes from Fabspeed

Andy,

How long has the Technotorque been installed? If it is a recent addition maybe there is a leak in the system and a clamp or coupling needs to be adjusted or tightened.

ddb

AndyA6 · 06-24-2011, 06:08 AM

Thanks guys!

Correct, there are no sensors. Either there might be a leak between the headers and the pipes or something came loose in the intake area...... who knows.

I will scan the car asap and see what code(s) there are. The TT is in for quiet a while now.

Whilst driving this morning to work I can def feel more power. Sound is very different now, deeper and a bit louder, me likey!

Also, carefully checked the dreaded 3200 rpm vibration, guess what, gone! As stated in my earlier post I felt some vibs at 3500 but today only (flat6) smoothness, like it should be.

Reporting back asap!

dennis · 09-28-2011, 08:29 PM

I have a clunk when engine is torquec hopefully from pipe too close something? Guys, anybexperience

AndyA6 · 10-01-2011, 12:31 PM

Quick update, stopped by at the dealership, car hooked up and it shows that the O2 sensors are actually ok, the heaters don't work, seemes to be a wiring issue.

Good thing my car is CPO, won't cost me anything to get fixed but I need to make an appointment first. I can drive and it won't hurt anything.

More after the repair!

insite · 10-03-2011, 02:54 AM

andy - the heaters are part of the O2 sensors.

FYI, theres is an O2 sensor heater circuit that runs through a relay in the trunk. again, when i had this issue, the heater on ONE of the O2 sensors was bad & it threw codes for all four.

FYI, a scanner still showed this sensor as functional. one has to physically measure impedance across the heater at the O2 sensor to be sure it works.

AndyA6 · 10-24-2011, 12:02 PM

CEL fixed!

Car was at the dealership and they replaced both secondary O2 sensors. The sensors worked but the heating element on both were shot. Even the tech who I know for many years was a bit baffled, he kinda suggested to put spacers in there..... he also thought that maybe the bipass pipes might be a reason, something like "less back pressure causes the heating elements to stay on longer thus causing possible damage" but we agreed that this is highly unlikely......

Let's see if the problem comes back.

Thanks all for the input!!

AndyA6 · 10-25-2011, 08:07 AM

BTW, the bill would have been 900 bucks, thanks to CPO I paid exactly nothing!

jmatta · 10-26-2011, 08:01 AM

I've had my bypass pipes on for years now and have never triggered a CEL. I imagine your's must have been a one off case.

AndyA6 · 12-30-2011, 03:24 PM

Sofar no further problems, no CEL or any other ill effects.

Love this mod!

Just a few days ago I installed secondary bypass pipes on my wifes Cayenne S. Very easy to do with the right tools, without the right tools not do-able.
Now, talk about a difference! Sound is way louder at WOT, more power as well. Idle and cruising same noise level as before.

Happy New Year!!!

Later,
Andy