Replaced my o2 sensor - P1115 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

CJ_Boxster · 01-26-2007, 10:02 AM

I replaced the o2 Sensor yesterday and all alot of the missing HP came back and im already noticing that my mileage is increasing, I drove the car atleast 20 miles and spirited too and the fuel gauge needle moved about a millimeter. Literally, the needle was touching the higher edge of the 1/4 mark on the gauge after the install of the new O2 sensor and after the spirited driving i did afterwards and the drive to work this morning... It now touching the lower edge of the 1/4 mark.

BTW, i have 104k miles on my boxster and when i replaced the 1 bad o2 sensor, i did not get the cel for the other 3 o2 sensors like some forum members experienced.

I also notice that my idle is SO MUCH BETTER, i dont get that little stumble during idle where the rpms will drop from 900 to nearly 400 then back up. Its solid now!

RandallNeighbour · 01-26-2007, 10:45 AM

glad to hear your box is running so much better. However, you may want to run through a couple tanks of fuel to see if the MPG is going up as fast as you think it is.

I do hope you don't throw codes for the other three now as well. I replaced one a while back with a used one that my mechanic had lying around his shop and it worked for a while, then I started throwing codes on another one so I just replaced all four.

If you think your car runs great with one new one, imagine what it would do with a whole set!

CJ_Boxster · 01-26-2007, 11:38 AM

Yeah, im planning on buying the other 3 within a 2 month period. My father has an account with worldpac so the OE type o2's ahead of the cat are $93 and the ones behind the cat are $73 so it wont take long to get them, I should ask his price on a Oil Separator too....

xclusivecar · 01-26-2007, 02:43 PM

I usually took me 1 week and approx. 200 miles of driving to throw another code after changing an O2 sensor...keep your fingers crossed!!

CJ_Boxster · 01-26-2007, 02:54 PM

1 week, hmmm man, well i hope it doesnt throw a code. Doesnt matter really cause im buying the 3 o2's anyway. I hope the car runs good if it throws the other 3 codes.

blinkwatt · 01-26-2007, 04:49 PM

Quote:

Originally Posted by CJ_Boxster

Yeah, im planning on buying the other 3 within a 2 month period. My father has an account with worldpac so the OE type o2's ahead of the cat are $93 and the ones behind the cat are $73 so it wont take long to get them, I should ask his price on a Oil Separator too....

I thought they were the same,pre and post cat?

CJ_Boxster · 01-26-2007, 05:58 PM

wires are different length according to the worldpac ordering menu

blinkwatt · 03-05-2007, 01:45 PM

Did you ever change out the other o2 sensors yet? How did swapping 1 o2 sensor hold up?

CJ_Boxster · 03-05-2007, 01:49 PM

Well i think the other members that replied to the thread are right about changing both at the same time, i need to use the odb2 scanner today to see if the others are throwing any codes... cant tell for now cause i have a CEL for the MAF already. Ill let you know if the other o2 is finally throwing a code.

MNBoxster · 03-05-2007, 03:35 PM

Hi,

You can't gauge changes to Range (MPG) by merely glancing at the gauge after driving only 20 mi. The DME can function differently through at least the first Drive Cycle before settling in and the gauge just isn't that accurate (for 20 mi., you'd be trying to gauge a fraction of a gallon).

You need to fill-up, reset the OBC and check it's results against how much fuel you add at the next fill-up to have anything useful, in addition to driving the same way over pretty much the same road/ driving/ load conditions...

Happy Motoring!... Jim'99

edevlin · 03-05-2007, 03:51 PM

"I usually took me 1 week and approx. 200 miles of driving to throw another code after changing an O2 sensor...keep your fingers crossed!!"

Ditto that, I have been chasing a P1275 CEL code that I started getting when I put on 100-cell cats and had the car chipped. I also replaced all 4 oxygen sensors at that time. We have been playing with moving sensors and we even replaced one of the cats that the code reader said was running at a low efficiency. Like clockwork at 120-125 miles after we mess with the system I get the P1275 CEL again.

BTW, we are really stumped by the error code. The car has had the CPU reprogrammed to take into account the intake and exhaust including the high-flow cats. The last time we looked we got the P1275 and it said the left bank was running at low efficiency, which means the cat or the oxygen sensor is acting up. We then swapped oxygen sensors on the left and right side and again got the P1275 saying the left bank was bad.

That made us think it was the cat on that side, which we replaced last week, I just put on 125 miles, and again got the P1275 CEL, any ideas on what might be going on would be greatly appreciated,

Ed

CJ_Boxster · 03-29-2007, 12:01 PM

Update here on my single o2 sensor replacment done 01-26-2007, I still havent gotten any codes for any of the other 3 o2 sensors. lucky me.

dcporsche99 · 03-29-2007, 02:19 PM

Hey CJ,
Very cool to hear! Unlike you, I had to change all four ASAP! I have actually been driving my garage queen these past few days that it has been nice in New York. I, too, am happy to report that after almost 200 miles so far, my CEL has remained off. But, of course, now that I have sent this info out into the universe....you know how that goes...lol!!

dcporsche99 · 03-30-2007, 08:07 AM

"...I have been chasing a P1275 CEL code that I started getting when I put on 100-cell cats and had the car chipped. I also replaced all 4 oxygen sensors at that time. We have been playing with moving sensors and we even replaced one of the cats that the code reader said was running at a low efficiency. Like clockwork at 120-125 miles after we mess with the system I get the P1275 CEL again...

That made us think it was the cat on that side, which we replaced last week, I just put on 125 miles, and again got the P1275 CEL,..."

Hi Ed,
Just wondering about your code. Any new updates??? Let us know what you've come up with.

Thanks.

BTW, I see that you have posted an update. I just added it here: Help with P1275 Error Code.

CJ_Boxster · 07-30-2007, 12:22 PM

Well still no extra O2 sensor error codes since replacing only 1 o2 Sensor

Rodger · 07-30-2007, 02:42 PM

Several of my Subaru buddies are using these to prevent those annoying codes. Those 100-cell cats are probably not as good at scrubbing the HCs out of the exhaust as the stock cats, and the O2 sensor is seeing it. How about a blindfold for the O2 sensor? These actually work.

http://www.voodooboost.com/performance_accessories/O2_Simulator/

CJ_Boxster · 07-30-2007, 03:43 PM

Those are the exact same thing as buying a Anti-Fouler from the help section of autozone. Did that to my buddys RSX Type-S after we installed a header kit that eliminated the cat.

steve00s · 07-31-2007, 08:04 AM

These pull the existing sensors out of the direct flow of exhaust. I have been wanting to put headers on my car but have not found an affordable solution to the 4 sensors needing to be accommodated. For those of you that really understand how the O2 sensors work, will this prevent CEL's (at least in theory)?

pecivil · 08-02-2007, 12:05 PM

ed,

since I put on the headers/cats I get the P1115 and P1116 and P1117 and P1119. The o2 sensors were all replaced with new stock too when the headers went on.

My mech and I think the problem lies in having to lengthen the o2 sensor wires to get to the new locations in the cats. At least in my setup, he had to lengthen the wires for both of the post cat sensors. The resistance of the wires changes as they get longer, and that may be what screws up the sensor.

I know my sensors are good, but the fault keeps getting thrown. But the car runs like a top, so I dont worry too much. It would be nice tho if something could be done.

edevlin · 08-09-2007, 11:24 AM

"...I have been chasing a P1275 CEL code that I started getting when I put on 100-cell cats and had the car chipped. I also replaced all 4 oxygen sensors at that time. We have been playing with moving sensors and we even replaced one of the cats that the code reader said was running at a low efficiency. Like clockwork at 120-125 miles after we mess with the system I get the P1275 CEL again...

That made us think it was the cat on that side, which we replaced last week, I just put on 125 miles, and again got the P1275 CEL,..."

"Hi Ed,
Just wondering about your code. Any new updates??? Let us know what you've come up with."

I have had the car in the shop for a week for them to play around with chasing the 1275 code. They found a number of interesting things. First, a possible small air leak on the intake after the mass air flow sensor (vacuum leaks of that sort have sometimes triggered 1275 codes). Small leak, but they fixed it.

They found one of the front oxygen sensors running a little low in efficiency (they replaced both front sensors), finally, they found that one of the 100-cell cats was running at slightly below normal efficiency (they replaced that Cat), yikes.

Its a 200+ drive home from the shop tomorrow, if its going to throw a code, it will do it on the way home, and I will be one unhappy camper. BTW, if the car is behaving itself on the way home tomorrow I think I will do a dyno run, as I have the dyno data from before these repairs.

Ed