hsheil

Hello all just thought I would close out this thread by reporting the resolution to my problem. Turns out there were multiple underlying causes to the symptoms I reported at the start: * a bad airlock; * cracked coil on cylinder two; and * an O2 sensor that was reporting incorrect readings (as reported by the Durametric package). The car solved number one itself with a massive burp of coolant after a particularly hard drive, giving me a scare in the process (initially thought the cylinder liner had gone - engine cut out, the engine compartment was soaked and a big cloud of water vapour out the back). Number two was solved as part of a 24,000 mile service. Number three (the O2 sensor) was solved by a fuel additive at the same time - I saw the outputs of the O2 sensors - the sensor ahead of the cat was continually reporting incorrect readings and oscillating back and forth - the fuel additive removed whatever buildup / something else and it's been fine since. The car is running well now - all of the torque and power is back again. Thanks for all the replies. Humphrey

Hi Loren thanks for the reply. No, no work done recently, this is a problem that just cropped up. Apart from needing a new coolant reservoir tank a few months ago, the car has been bullet-proof for the three years I've owned it - no problems at all. The misfires always happen after the P0134 as far as I can tell. The reason that the log I posted has four misfire codes after the P0134 is because I had to carry on driving the car after the CEL came on. I will check the coil packs et al. as well though to make sure. The car has 110k miles on it, the MAF was last replaced at about 90k miles. The vibration started at exactly the same time as the rough running and intermittent misfire that's why I'm assuming they are all symptoms of the same problem. Humphrey

Hello all Car information: 996 Carrera 2 coupe, model year 99, 6 speed, UK model. Brief problem description: Constant rough running, periodic engine misfires, reported P code associated with misfire events is P0134 (Oxygen sensor ahead of catalytic converter (cylinders 1-3) on Motronic 5.2.2 readout), noticeable engine vibration at circa 3,000 rpm. Advice needed on how to rule in / out MAF, O2 sensors etc. More detailed problem description: Recently my car developed a misfire. I ordered the Durametric hw/sw and saw that the EMU was reporting a P0134 code. I have read all the posts on this forum on MAFs and decided to clean the MAF using electronic contact cleaner. This definitely helped - the misfires went away for circa 700 miles, however an engine vibration over 2,800 RPM remained. The engine also sounded rougher and I felt that the car did not have the power / torque it had before (but those are subjective opinions, it's easy to start imagining things!). About 100 miles ago, the misfires returned, caused by the same P-code - P0134. I cleaned the MAF again and again this has temporarily solved the problem but I want to fix the problem properly and get rid of the noticeable engine vibration / noise and get the missing torque back. I'm asking for advice on: * How can I identify if the problem is a MAF problem or an O2 sensor problem or indeed something else altogether; * After I clean the MAF, does wiping the P codes using the Durametric package also reset the EMU or do I need to disconnect the battery in order to do this (and should I be resetting the EMU at all); * If it is the O2 sensor problem, do all sensors need to be replaced together or can they be replaced individually; * What features of the Durametric package can I use to help isolate the faulty component; * will replacing a faulty MAF / O2 sensor (if it isn't anything else) solve the vibration and perceived lack of torque symptoms that I have also noticed. Thanks in advance for your replies. Humphrey PS Here is the last output I read and saved using the Durametric package. P0134 Factory Fault Code 10 - Oxygen sensor ahead of catalytic converter (cylinders 1-3) Interruption of signal P0300 Factory Fault Code 75 - Misfire damaging to catalytic converter P0302 Factory Fault Code 64 - Misfire, cylinder 2, damaging to catalytic converter P1319 Factory Fault Code 62 - Misfire, emission related P1314 Factory Fault Code 51 - Misfire, cylinder 2, emission related