Code P1128 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

PorscheGirl · 08-10-2005, 06:03 AM

I have a 2000 Boxster. I was on my way to work yesterday, almost completely stopped in morning traffic, and my check engine light came on. The car didn't seem to be running any differently. I stopped on the way home from work at an autoparts store, and they plugged it into a computer and told me that it was code P1128. After reading all the posts here, I double checked the oil and gas caps. They were fine. The light is still on. I guess my question is now what? Should I have had them reset it, or can they? Should I give it a while to "reset", or does that have to be done manually? If so, then is that something I can do myself? Keep in mind that I am a girl with little or no idea what I am doing, but am completely capable of following directions! : ) Thanks for any advice.

Brucelee · 08-10-2005, 06:31 AM

I don't know what the code is but your Porsche dealer will. Perhaps on a phone call, if you ask nicely they will tell you.

Personally, I would NOT reset it unless I new what the code was. It might be something minor, but ........

Good luck.

deliriousga · 08-10-2005, 07:40 AM

Hey PorscheGirl,

I answerd your question in the previous thread you posted in at CEL (P1117), Any Advice?

You can drive the car until you take care of the problem. Just don't put it off. When mine went out, the dealer said I could drive it with no problems until my appointment that was 3 weeks away.

PorscheGirl · 08-10-2005, 10:37 AM

I think that I am going to have the guy at the autoparts store try to reset it and see if it comes back on. If it does, I will worry about it then.

I have 50k miles on it and it just had the 48k mile maintenance on it right before I bought it. When I got it it had 47,600 miles on it. I bought it certified pre-owned from a dealer right after the 48k maintenance was performed. I'm hoping that the reason the lady got rid of it was only because of the lease ending and not because they found all kinds of problems when doing the scheduled maintenance!

deliriousga · 08-10-2005, 12:18 PM

Good plan.

If it comes back on see if the dealer will take care of it for you. Since it's "certified pre-owned" there should be some kind of warranty on it.

I wouldn't worry about too much being wrong because of this. Sensors, no matter what car, are very sensitive and the get dirty or go out all the time. At least it's just an O2 sensor so the car still runs.

Good luck!

ddb · 08-10-2005, 01:11 PM

PorscheGirl,

I had a 1128 in my 2000 earlier this year. I had the CEL reset after adding a bottle of Techron gas additive. I didn't have any problems until I had another CEL recently. I was sure it was another 1128. Instead it was a 1117. I reset that one as well. Since I haven't found anything loose or disconnected in the engine compartment, I tend to think it's an O2 sensor. I'm planning on replacing all 4 O2 sensors very soon. Let us know how this turns out for you.

ddb

PorscheGirl · 08-11-2005, 05:14 AM

I had the guy at the autoparts store reset the code on my way home from work last night, and so far so good. I'm going to keep my fingers crossed that it was just a fluke. What are the odds that it could be so easy?

deliriousga · 08-11-2005, 06:48 AM

Quote:

Originally Posted by PorscheGirl

I'm going to keep my fingers crossed that it was just a fluke. What are the odds that it could be so easy?

Glad to hear it's good for now. I'd call it more of an early warning like ddb was hinting at than a fluke. Hopefully it will last a while, but don't be surprised if it pops up again in the next few months.

ddb · 08-11-2005, 02:21 PM

Porschegirl:

I agree with deliriousga, unfortunately I think it will rear its ugly head at some point down the road. It may help to run Chevron gas in it, or add Techron fuel additive to a full tank of another brand of gas. Let us know if it returns.

Good luck,

ddb

PorscheGirl · 08-17-2005, 05:22 AM

Well, sure enough, the light came back on this morning on the way to work. That didn't last very long! It was the same scenario. I was just sitting in stopped traffic when it popped on. Is it possible that it was the gas that I put in it? I always fill up at the same station (BP), but this last time I went somewhere else (still BP, but another station). I am going to take your advice and try Chevron w/ Techron. What exactly is Techron and why is it helpful?

Does anyone know if this is something that would be covered under an extended warranty? (If it is in fact an O2 sensor)

Brucelee · 08-17-2005, 05:50 AM

Time for a trip to service dept. Re: warranty, it depends which one you have. Check our contract.

Let us know what how you make out.

deliriousga · 08-17-2005, 08:06 AM

Quote:

Originally Posted by PorscheGirl

I am going to take your advice and try Chevron w/ Techron. What exactly is Techron and why is it helpful?

It's viagra for your engine. :dance:

Really, it just helps keep the engine from collecting deposits in the fuel system. Keeps your injectors from clogging and such. Deposits in the system can cause the engine to run poorly or go beyond the thresholds of the 02 sensors. You can buy bottles of it at most auto parts stores if you don't have a Chevron nearby.

spgribben007 · 08-17-2005, 11:28 AM

How often should someone use additives like Techron? I know it improves gas mileage and with today's gas prices it's a smart thing to do but what is too much? Every 10,000 miles? 5000? 3,000?

deliriousga · 08-17-2005, 12:21 PM

Quote:

Originally Posted by spgribben007

How often should someone use additives like Techron? I know it improves gas mileage and with today's gas prices it's a smart thing to do but what is too much? Every 10,000 miles? 5000? 3,000?

I wouldn't count on saving $$ due to higher gas mileage if you have to add bottles to other branded gas. The cost of the stuff is >= what you will save due the little bit of higher mileage you may get.

If you get the Chevron gas, it's in every tank. If you have to add it from the bottle, I'd put it in every tank, but I'd find out how much is in put the Chevron gas and match that amount.

All in all, it's easier and cheaper just to put the Chevron gas in it rather than buy the bottles (or Texaco now that it has Techron added too

)

ddb · 08-17-2005, 01:54 PM

"All in all, it's easier and cheaper just to put the Chevron gas in it rather than buy the bottles (or Texaco now that it has Techron added too )"

deliriousga:

Unfortunately I don't have Chevron stations in my area. I was thrilled to learn a couple of weeks ago that Texaco now included Techron in their gas. It's now the only gas I will burn in the 986.

PorscheGirl:

I don't know if O2 sensors are covered under warranty. I would take it to the dealer and see what happens. Please let us know how it all turns out.

Best of luck,

ddb

PorscheGirl · 08-19-2005, 07:34 AM

The saga continues....I filled up on Wednesday and have driven it about 40 miles since and this morning when I started up, the light is off again.

Hmmm....car seems to be a little fickle!

I have invested in a code reader from ebay for $30, so I will be ready for when it comes back on. I'm hoping that I just got some bad gas the last time. That is when all this started, with that tank of gas. We shall see..........

Thanks for all your input.

Brucelee · 08-19-2005, 07:37 AM

Not to be a pain but why not just take it in and get it repaired by a competent mechanic?

selbox · 08-19-2005, 10:04 PM

from renntech.org

P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold

whatever that means

http://www.renntech.org/forums/index.php?act=pcode&code=menu

deliriousga · 08-20-2005, 06:50 AM

[QUOTE=selbox]from renntech.org
P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold
whatever that means

QUOTE]

It means the fuel/air mixture has passed the rich threshold on the cylinder 1-3 bank. Too much fuel is put in the mix (rich) so some of it does not ignite in combustion. The fuel that does not ignite goes down the cats and the 02 sensor detects fuel beyond it's pre-set threshold. The computer tries to adjust the mixture, but if it cannot get it down below the threshold it assumes there's a problem and you get the code. There is a threshold set because even in perfect mixture conditions there is a little fuel that does not ignite. It's usually the 02 sensor going bad and creating bad readings.

This can be dangerous because too much left over fuel in the really hot cats can give you a cat fire.

Hope that helps.