OBDII code 1123

Can anyone confirm this is the code for replacing the O2 sensors? I did a search and could find an answer. Loren?

O2S Sensing Range 1 Cyl. 1-3

I wouldnt jump at changing the oxygen sensor yet. That fault is triggered set when your DME is either having to add or subtract fuel past a certain amount. It could be any number of things, from a dirty MAF sensor to a vacuum leak. The only way to know for sure is to look at your TRA and FRA numbers from the DME but I'm not sure if you can do that without an PST2 or PIWIS tester. Taking it to the dealership may be cheaper than throwing parts at it.

are cylinders 1-3 on the right or the left??

what is the error code for cylinders 4-6??

Take the car out on the road and see if it bogs down at 4000 rpm and seems to lag above that. Its probably a bad MAF. ( I had this twice and it was the Mas AIr Flow sensor each time)

Bank 1 is the driver's side.

P1124?

P1123 - Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold Fuel/air mixture is so rich that sensing is up to its lean threshold. Most likely causes: Fuel pressure too high. Fuel injector leaking. EVAP canister purge valve open.

thanks for that loren, as always a great help. i removed the aftermarket intake kit as someone recommended looking for vaccuum leaks, i think it may have something to do with the light...i reset it and so far it hasn't come back. Before removing the intake, the light would come back after a reset within a mile of driving, now i've done 50 or so and nothing could this condition be caused by a "powerchip"? am i right to assume that only a dealer's scanner is going to tell me exactly where the problem lies?

Usually "powerchips" don't cause a CEL. If they did they couldn't sell them. The dealer's PST2 (or PIWIS) will not tell more than what I told you above. Someone still has to eliminate potential causes... or jump to known (historical) failures.

In my opinion, yes. Actually a PST2 or PIWIS will tell you a ton more than just the fault. If all you needed to diagnose a car was the OBDII fault then dealerships wouldnt be buying PIWIS testers for 5k a pop. It doesnt seem like you've actually used either the PST2 or the PIWIS. If you have you wouldnt make a statement like that. Seeing the acual values from the DME will tell you a lot. He might be .01 away from setting a fault for bank 2. It would tell you what his range two (FRA #'s) numbers are which could help you by telling you if the problem was just in the idle range or if it carried on through the load range. You would be able to read MAF voltages and airmass numbers plus about a million other things (most of which I have no idea what they are, hehe). Im not a P21 guru but his fault indicates hes hitting the lean threshold which means to me the computer is taking away fuel. A faulty fuel pressure regulator would be enrichening all cylinders therefore it is likely he would set a fault for both cylinders 1-3 and 4-6. I suppose a leaking fuel injector could cause this fault and this is where the PST2 or PIWIS would help out in looking at your acual values. If he had an evap valve stuck open he would have other faults as the EVAP system does a self test (if certain conditions are met) every time the car is started and sets a fault if it doesnt pass. Without knowing where is FRAs are it its very difficult to diagnose his problem.

With all due respect I have used a PST2... and it will allow you to read a few test points but i does not come up and say change the MAF - which was my point. And... dealer cost on a PST2 is under $4000 (at least for the dealers I inquired with).

I believe I had the same CEL code. Cause was a leaky oil separator bellows...

A few test points? Haha ok if by a few you mean like 100. I'm not sure If i get what you mean with "Change the MAF." Sure the testers are not going to come out and say "REPLACE THE MAF SENSOR," in plain english. Thats up to the tech to diagnose. The way to diagnose it is with TRA and FRA numbers, not the ODBII fault code. Without the numbers the fault code, especially this particular fault, is practically useless. If dealer cost on a tiny screened black and white display PST2 is 4 grand imagine what a PIWIS (Full color, touch screen) is gonna cost.

Before the across the board nearly 50% parts price increase in August, dealer cost on the PIWIS tester was around $9000USD plus $1200USD monthly subscription. The only problem is Porsche is only selling 1 unit for every 3 techs a dealer has. Good luck buying one but if you do find a dealer willing to sell one please let me know cause I'm looking.

thanks for all the input, i think it needs to go to the dealer if the code reappears. so far less the aftermarket intake, the code has not returned... nice picture of Spicoli, "make up your mind dude, is he gonna **** or is he gonna kill us"

"first he's going to ****, then he's going to kill me."

OBDII code 1123 is "oxygen sensing adaption area1 ( cylinders 1-3) Lean Threshold I have the complete OBDII manual if you need the rest of the problem and repair its about 4 pages just for this one code.

I get this same code along with 1124 (cyl 4-6) at the same time. I have gotten it reset and it takes about 300-400 miles before the CEL goes off again - same two codes. I was told it was running slightly rich, barely out of spec and they suggested resetting it. If this was a vacuum leak, wouldn't it go off right away? Why would it take a few hundred miles before the CEL goes off again?

BTW, all of this was happening before I installed my exhaust and intake mods. Just thought I'd state that before someone suggested that might be the culprit.

1123 means cylinders 1-3 are lean and 1124 means they are too rich. If you got code 1125 that would indicate that cylinders 4-6 are lean.

Hate to resurrect an old thread but.............. any others have luck with the 1123 1125 codes. Just replaced an oil seperator, with no luck. Any other ideas?

The code indicates that your exhaust on Bank 1 is RICHER than the limit allows. Your O2 sensor has tried to lean out the injectors as far as it could, but reached it's limit and threw a code. There are many things that can cause a rich confidition in your engine. You could have a leaky injector or too much fuel pressure or a problem with the evap system. It also could be caused by a bad O2 sensor. However, I would first eliminate the easiest thing first, and that is the spark plugs. If one of your plugs on bank 1 is not up to snuff, it wouldn't burn the fuel mixture completely and the very rich mixture would be picked up by the 02 sensor on it's way out the exhaust. When was the last time you changed your plugs? Do you smell gas in the engine compartment when the engine is idling? Are you now getting a code of 1125 with the 1123?

Do not smell gas, I don't know the history on the last spark plug change. Yes 1123 and 1125. Thanks!

Update on PIWIS units. The current price on a PIWIS is $22,000 plus a 5 year lease at $11,000 per year annual subscription fee.

It DOES NOT mean the engine is LEAN. It menas the engine is RICH. The causes for this code is the same for all DME versions.

My Boxster had the same codes,P1123 and P1125 come on at the same time. The car hesitates at times to gun it,but other then that no issues at all. If both codes came on at the same I would think it is the MAF not doing its job. What are the odds of oxygen sensors going bad at the same time? I cleared the light with my OBD II reader but the car still hesitates at times and I beleive it is only a matter of time before the light comes back on. Iam going to attempt to clean my MAF sometime this week.

In the 7.8 manual a bad MAF is the first listed probable cause. It's probably the MAF.

But the Boxster doesnt use 7.8 it uses 5.2 or 7.2 depending on the year of the Boxster....