Ok so my 2005 Carrera has been giving me a few problems. I have the charging issue which I have narrowed down to my battery cable. But I also found an oil leak. I discovered the AOS hose is loose right behing the AC compressor. Is there a way to tighten that hose down? I have been getting misfire codes on almost all cylinders lately. I replaced all plugs and coils with no luck. Codes came back! Any chance just the AOS hose being loose and blowing air out can cause a misfire code? Thanks guys!

Darren

 

Upate: Turns out the tube is completely cracked through. I need a whole new tube now.

 

Hopefully it's good for the next 7 years.

 

Hey Signature65,

Did you repaced the AOS hose? Did all the misfire cylinder problems got fixed? I am running into same issue with multi-cylinder misfires and last week I noticed a very small oil leak after taking off and placing back the air filter box. The oil leak stoped, but did not verified where the leak was coming from. I am still having issues with these code:
P0300
P0303
P0304
P0305

Please let me know. Maybe I have the same problem.

Thanks!

 

I ended up pulling the intake to replace my alternator cable because I had the notorious hot start issue. When I had the intake apart there was noticible oil in the intake manifold. So I replaced my AOS and the tube all at the same time. However it is still loose where the hose attaches to the block behind the air conditioning compressor. So I imagine I have to replace that connection too. It does start like a champ now but i havent really driven enough for the light to come back on. It ususlly took 3 days of active drivig before the light came on again. I have been busy at work and the car has been sitting. I will keep you posted if it comes back.

 

Thanks for the feedback. My 997 is a daily driver and I have been having issues with misfires. So far I have replaced the spark plugs and MAF sensor. It hesitates the most when engine is cold, but the exhaust sounds funny even when hot. I am sure is related to the misfires. The car runs good, but hesitates at slow take offs. Mostly noticeable with cold engine. Might take it back to the shop this weekend. Any suggestions? Thanks.

 

Going through the same situation. I have misfires in all cylinders few minutes after start ; the CEL comes on every 2500-400 miles. The car feels and drives fine. I've left it with the mechanic for a week but they couldn't reproduce the fault. I' ve changed the plugs and coils with no change in the pattern... I have a 2005C2 with 36000 miles. The only mod is Borla cat back. At this point I do not know what to do...

 

I fixed my misfire codes by changing the MAF sensor. Bought it from Pelicans for around $260. My small computer was not giving me the code for the MAF, but the mechanic apparently was able to get this code. I fixed the problem over a week and no more codes. Are you seeing any hesitation while the engine is cold? Mine used to do that. Good luck!

 

Thanks for the idea Luigi007. I didn't notice the hesitation when cold, just a bit of rough idling after cold start. It happens 1-2min after cold start and and settles down when RPM come down to 700. If I reset the codes, it takes several hundred of miles for the light to come on again . I will disconnect the MAF and see if this will take care of my issue.

 

I tried to disconnect the MAF and it ran better. The engine will start and then it will die. This is while the computer is switching to limp mode. I also hear that you can get unreliable results with the disconnected MAF. You might be able to test the MAF sensor. Also, make sure that all the hose clamps are tight between the air box and throttle body.

 

After I disconnected the MAF the engine started but died right away. I tried again and it stayed on, but the idle RPMs were going up and down between 600 and 1200. After several minutes it idled OK. The car ran fine but once or twice I felt it did not have enough power to do certain maneuvers(I guess because of the limp mode). I hope my problem is the MAF...Thanks to the info I got from Macster and after reading multiple posting on misfire in all cylinders it makes sense to me that it should be a problem with the air/fuel mixture; somehow the engine gets a lean mixture on occasion when cold(my MIL never flashed). But unfortunately there so many sensors/inputs that can complicate the picture... For now I will try the MAF pathway to see if I am going anywhere... I'll keep you guys posted.

 

I also tried the whole disconnect the MAF when I was trying to diagnose my problem. My car ran always ran fine with no hessitation but the occasional rough idle. Thru the RPM's it always ran fine. My results were inconclusive with my MAF disconnected. I dont drive my 997 daily so judging exactly how many miles before the CEL came back on was always a mystery and not consistant. With it disconnected the car ran fine. No loss in power and no notible change. I did read somewhere that you shouldnt really go over 4K in revs with it disconnected, so I was driving pretty mellow. In the end after a Busy month at work I am finally driving my car again after changing the AOS. We'll see if the code comes back.

 

Quick question for Luigi: how is the car running? Any new MIL after you changed the MAF? How many miles driven since the new MAF? I just got my CEL back today, 1500 miles since the last incident. Still the same codes 300-306.

 

Yes. I got misfire codes back again. I decided to take my car in to San Antonio Porsche dealer. I just got my car back today after spending $500 dollars. They cleaned the intake system and updated the computer software. The car feels more responsive and idles better. They also recommended me to use gas from main gas stations like Chevron, shell, etc. I still feel a small lag when pressing the gas pedal from idle speed specially when engine is cold. The mechanic told me that if the lag continues I might need to replace throttle body. He said that he swap it with another car and the engine ran perfect. At this point I am going to try with original throttle body. I will update the forum in a couple of weeks.

 

Thanks for the update. I feel that it is very difficult to solve this random misfire problem. Looks like one can spend a lot of money and time and the problem still persist.