BimmerFest BMW Forum banner
1K views 16 replies 4 participants last post by  bmwmanz2 
#1 ·
Hey guys. I am new to the forum as of today. I guess you could say new to the member's list as I have read quite a few posts rather then been able to respond to them. I have a question that someone might have an answer to. I have a peake scan tool that has read my codes. The codes listed were the following: 1. camshaft position sensor 2. crankshaft position sensor 3. o2 adaption limit reached cylinder 1-3 4. o2 control limit reached cylinder 1-3. I did a visual inspection of the intake CPS and the bolt was loose and not making a seal. I took it out and cleaned it up (including the o-ring) and tightened the screw. I then erased the codes and have driven it more than 200 miles and the codes have not come back(CPS and CKS). My car was having trouble starting to where I would have to relieve the pressure on the fuel rail in order to start it every time :(. After that intake CPS was cleaned and properly tightened the CPS and CKS codes were gone and started like a champ. My only concern now is to get the other two codes gone so that my CEL will go off. What does o2 adaption limit cyl 1-3 mean? What does o2 control limit cyl 1-3 mean? I have visually checked the PCV or CCV (whichever one it is going from the valve cover to the correct valve) and cannot tell visually if there are any cracks. I unplugged the MAF and let it run. It did throw the code, so I know that is functioning properly, so I plugged it back in. The throttle body boot is brand new, so I doubt that could be it. I have no idea how to do a smoke test if it is a vacuum leak. I have cleaned the ICV and throttle body. I have a new IAT from previous maintenance. I guess I am asking for what other kind of information you guys would need or things I could try?

Thanks so much.
-Tony
 
See less See more
#2 · (Edited)
how many miles do you have?

what are the codes remaining? pxxxx pxxxx

cylinders 1-3 are the first 3 starting at the front/radiator side. curious why its only 1-3 and not 4-6 also.

i think p0171 and p0174 are the vacuum leak codes

try things in this order:

have you tried cleaning your MAF?

checked the intake boot and connecting hoses? some deteriorate, break, or crack.

check your disa valve/ the 0-ring gasket on it.

clean your ICV.

checked your CCV hoses? they get brittle and crack/break also.

have you changed the pre cat o2 sensors?



if you havent changed your precat o2 sensors it will be on the list soon enough to do. however i would probably wait and do this last as it will cost the most.
 
#3 ·
For your first question, I will have to give you a funny response. The mileage on the engine has 284k on it, but many new parts. The engine that had a blown head gasket(in my parts car) has 150k. The tranny has 152k on it. I am sorry for such a confusing response. The codes remaining are O2 control limit cyl 1-3 and O2 adaption limit cyl. 1-3 from my Peake fcx-3-u Scan tool. As for the MAF cleaning, I have cleaned it with the CRC MAF cleaner and tested it. Everything is running fine I assume in that area. I do have the common rough idle on cold starts that smooths out. I just need to get this fixed for my future move requiring CEL to be off and so that my fuel economy gets back up to where it usually is (comb 25..city 20-22..hwy 29.7+). The intake boot...this is right after the MAF connecting to the throttle body? If so, it is brand new, but I will check the hose connecting underneath. I have changed all 4 O2 sensors on my '97 giving them all ~30k on them. I bought the '98 and switched the ~30k O2 sensors on it being that I was unsure if/when the previous owner changed them having 150,000 miles on it. I really appreciate the help and quick response. I made the typical noob mistake apparently, so I am searching through the forums now ;)

-Tony
 
#5 ·
there is an F connector on the intake boot towards the throttle body the hoses on that get brittle and break and there is also a tiny elbow below that could be the cause also. just carefully inspect.

if you dont find anything there move on.

have you checked the DISA valve? there could be a leak there. its right above the ICV.

what about your CCV hoses? when was the last time you changed those? you can try the plastic bag test. open the oil cap start teh car and put a plastic bag over it and see how much it sucks it in.



another thing you may consider is searching the e46 forums if you cant find anything in here. thats always my back up if i cant find info on here.
 
#7 ·
do the plastic bag test for the CCV. search it on this forum.

the rough start up goes hand in hand.

either way it will need to be replaced. 200$ for the hoses and about a 6 hour job to do it yourself. there are DIY on here for it. its pretty straight forward just time consuming.
 
#8 ·
the adaptive limit is a preset parameter in which the long term and short term fuel trim will be as far they can go (either leaner, "-", or richer, "+").

this is reflected in a % (iirc) and will be listed in the freeze frame data next to the long term fuel trim (ltft) and short term fuel trim (stft).

the pcm (dme) will monitor the swing of the o2 signal, and adjust the fuel trims according to the response of said signal.

the good news is the o2 signal can be checked directly @ the sensor wiring with a power graphing meter or oscilloscope to get a visual on this signal. the multimeters will not have a fast enough sample rate to get a proper reading, so i do not recommend trying.

since this is only on bank 1, the first culprit i would round up is the actual o2 sensor itself. a dual trace meter would be able to inspect both primary o2 sensors at the same time to compare (the best way to test them, actually) and see is, in fact, the bank 1 sensor is lazy or not.

when o2 sensors get old, they tend to fail with lower than actual readings, indicating a leaner condition. this, in turn, tells the pcm to richen the mixture on the corresponding bank. once the limit (think of it as an electric fence for the dog) is reached, however, the pcm lets you know.

no actual driveability issues may be present when this happens, though, which is why it is imortant to remember to take a look at and record the freeze frame data.


hope this helps you understand what 'out of limits' means when it comes to o2 sensors.

as to what would cause it to do so, could range from a faulty sensor, to chafed wiring, to some other fault. it'll all depend on which side of the limits parameter you are looking (rich or lean).





df
 
#9 ·
Thanks for the info df. I don't have access to those kinds if tools, but when I do...I will have the knowledge ;). It does help me understand a bit better. As for the plastic bag test...I will get the searching on that as well. What if I switched the bank 1 and bank 2 precat o2? If I hooked up the scanner and it said the same but with cyl 4-6- would that be if indication that it is the o2 so swap it?
 
#10 ·
wouldnt hurt to try it. just be careful with the tips of the sensors.

if it moves to cyl 4-6 its likely your culprit.

also if you havent done your CCV id probably get that out of the way as big of a pain it is.

i spent a whole saturday on mine. then the next 3 days with a sore back, hamstring, and quads. glad its done and over with. vanos is my next back breaker.

good luck and report back.
 
#11 ·
Haha. My banks is already done thought the engine has so many high miles. Looking to get a head gasket for my 150k engine if it isn't warped or cracked. The CCV should be no problem and a fun project. I cannot recall the location, but that is what a Bentley manual is for ;). Plus doing an engine swap makes the CCV look like an oil change eh? Thank you too for being of such help.
 
#14 ·
So the fuel filter will have the fpr too? I have had not more problems after making a Seal with the CPS and cleaning it, but it was used so I haven't change the fuel filter yet. I know it would be wise, but was trying to get this pesky CEL off so inspection will pass.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top