update on exhaust issues... can anyone help?

[mn box s]

Some of you have read my other posts about my exhaust. I think I'm getting close to solving, I have a new check code. My exhaust is on a 00' S, set-up is Che's headers, Fabspeed test pipes, Che's exhaust. Yes that means I have no cats. Che sent me 02 sensor cheaters... the ones that back the 02s out of the exhaust pipe. The rear sensors I just plugged in and zip tied them up and out of the way. The 02s are new so is my maf. The check code is now p1115. Something about pre heating the 02s? Help me please. and thank you.

[j.fro]

You may have a bad O2 Sensor. You can check this by switching them (move left one to the right, and right to the left). Clear the codes, and go for a drive. If you get a CEL with a 1119 code, then it's the sensor. 1119 is the same code as the 1115, just for the other side.

[mn box s]

front? rear? or both?

[derb]

I currently have a similar issue- I have both P115 and P119. I bought new O2 sensors after my header install and both codes came up. I found a thread on another forum that said the resistance on the two heating wires should be between 1.8 and 2.5 ohms. My new ones were 3.4. The old ones were 2.5. I contacted the manufacturer (SNG) and they said my new ones were defective. I returned them but have not purchased another set yet.
Might be worth it to check the two white wires on both sides.
Good luck.

[mn box s]

I don't want to rule that out entirely, mine are Bosche exact replacements oem. I want to say that its probably not my problem. How do I go about testing the resistance I have a expensive fluke that willm do the trick. Was this from your rears or your fronts??? my guess is its from my rears that are not in any pipe currently??? Can anyone else chime in???

[heyjae]

P1115 is the pre-cat, passenger side sensor. The fluke will work in testing resistance. O2 sensor heating code issues seem to be popular. I'm trying resolve mine too.

[Jaxonalden]

This is just my opinion. To do their job, your O2 sensors need to read the O2 levels. The sensors are different before and after the cats because the resistance will be different when reading the exhaust gases because of the temp of the re-burning of the hydrocarbons. That re-burning confirms (through the O2 sensor) that the engines computer has the correct air/fuel ratio for the current conditions. When the oxygen sensor fails (or in your case removed and not reading the O2 in the exhaust), the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to. It will also throw up a code to your computer saying "the O2 sensor is bad".
You wrote "The rear sensors I just plugged in and zip tied them up and out of the way". Those sensors aren't reading a thing! No wonder they threw a code.

[mn box s]

I realize. No cats here. Most people that run no cats will tie the rears up. I guess my next step is to weld in bungs for the 02 and try another set of cheaters on those. From what I have understood though was that the wide band 02s are the front ones and the closed loop 02s are the rears to double check whats going on in front of them. Thats why on other cars you can get away with tying them up.

[Jaxonalden]

I don't know the particulars about what parameter each O2 sensor monitors, but I do know that the ECU needs inputs. Those inputs include the O2 senors and if their transmitting bad info, or info out of tolerance, it will flag a code and the engine will not run efficiently.
I hope someday a computer nerd will develop some software that will allow the Boxster the use of running with no cats (off road use only officer ). Sounds simple to me.

[mn box s]

Originally Posted by Jaxonalden

I don't know the particulars about what parameter each O2 sensor monitors, but I do know that the ECU needs inputs. Those inputs include the O2 senors and if their transmitting bad info, or info out of tolerance, it will flag a code and the engine will not run efficiently.
I hope someday a computer nerd will develop some software that will allow the Boxster the use of running with no cats (off road use only officer ). Sounds simple to me.

So are there no computer flashes that can correct this problem?

[SilentThunder]

Ya, its called the european tune. Just flash it with a ROW computer and it doesn't read the cats. An australian member runs catless because of this IIRC

[Topless]

Originally Posted by mn box s

I realize. No cats here. Most people that run no cats will tie the rears up. I guess my next step is to weld in bungs for the 02 and try another set of cheaters on those. From what I have understood though was that the wide band 02s are the front ones and the closed loop 02s are the rears to double check whats going on in front of them. Thats why on other cars you can get away with tying them up.

Or... You could put the cats back on, the o2 sensors back in and drive a smog legal car that runs great and has no error codes. Just a thought.