binger

If you just want the connector I am sure you can get it from http://www.ladismantler.com/

If you don't find a source for your gear try a used trans form la dismantler. They have your trans for $250 see the link below. I have been dealing with them for years. They are very helpful and have reasonable prices. http://www.ladismantler.com/parts/model?category_id=88&id=37

What was the code?

If the car was smoke tested with out any faults found you only have part of the data. Has anyone looked at the fuel trims or put a fuel pressure gauge on the car? do you have any power loss when you get on the gas? The most important information at this point are the fuel trims.

You may have a drivability issue that needs to be diagnosed by looking at your fuel trims to determine what area to focus on. I am not going to guess however what you describe could be a fuel regulator/ leaking injectors, vacuum leaks etc. You can have all or anyone of these issues without throwing a CEL. Go see someone that specializes drivability issues to solve your problem.

Yes Bosch is the OEM MFG of Porsche 02 sensors however there are several part numbers available for your application. Just be careful you are getting the correct cross reference part number. Also there is a TSB from Porsche on the 986 series see below. http://www.renntech.org/forums/files/getdownload/375-388boxster-oxygen-sensor-connectionspdf/

Just be sure you are getting OEM sensors not aftermarket. You are asking for trouble if you end up with an aftermarket sensor and not worth it to save $30.00 +. As a CA licensed smog tech I will not even do the job if the customer wants non OEM sensors as I have had too many come back to bite me.

unplug and inspect each connector one by one starting with the trans and look for bent pins, pins that have been pushed back in the connector or missing pins.

I forgot to mention to first look at all your fuses! If all are good then back track to what you unplugged and then replugged.

If everything was working before you R&R the motor and trans I would back track your steps. I would unplug and inspect each sensor starting with the trans and look for bent pins, pins that have been pushed back in the connector or missing pins. If all looks ok then you are going to have to test each sensor to prove them out. Also carefully look for damaged wiring or sensors that might have been plugged in wrong. Its going to take some time but you will find it. Diagnostics is about being patient. Please keep us up to date.

Hi, Can you please give us a complete history of the car. IE: why did you R&R the motor, manual or trip trans, did you do any other work to this car, did you pull the trans with the motor? Or did you just R&R the motor? Did you use the sensors from the original motor or did you use what came with the rebuild or replace all with new sensors. Do you have a Durametric scanner? If so can you please look to see if there are any pending codes?

After reviewing all the data you posted I agree with Ahsai and do not think you have leaky injectors. Without having the car in front of me my hunch is you have 1. the 02 sensors connectors have dirt or corrosion 2. vacuum leak 3. unmetered air just after the MAF or at the exhaust just before the o2 sensors that is fooling the o2 sensors to command more fuel. If you look at your screen shots the o2 sensors are switching at 0.4 mV to 0.74mV and giving a lean bis or low voltage command to the DME it see that as the motor is too lean. The DME now commands the injectors to add more fuel by making pulse width longer. Also the fuel trim on your car is 24% and 19% normal should be no more than 10%.Before you start looking for vacuum leaks I would also revisit the TSB on the 02 sensors as it is a quick and simple test to see if they start switching at normal rate. If the connectors have any dirt or corrosion this could add resistance thus giving a lower voltage to the DME. Porsche hates to admit any fault but this TSB shows that 1999 was a bad year for 02 sensors. The TSB states Proper care of oxygen sensor connections It is extremely important that the oxygen sensor connectors be clean and dry at all times. Contact cleaners, contact enhancers (such as Stabilant 22A), oil or water based sprays, and even die-electric compounds MUST BE KEPT AWAY from the oxygen sensor connections, or permanent SENSOR DAMAGE will result! Always clean oxygen sensor contacts in a dry fashion, being careful not to allow any type of substance or debris into the connectors. Note: The connections at the oxygen sensor can often be improved by simply unplugging and re-plugging the connector several times.

Your electrical engineer did you a real disservice. You should never use crimp connectors on anything that has to do with airbags or any on board computer systems. SRS systems are very sensitive to resistance and you are asking for trouble. Just the fact that you have made the wire longer by adding connectors is a big no no. Over time your SRS will light up because of an improper connection or corrosion. Most OEMs will call for a new harness if there is a cut wire or bad connector Porsche is one of them. BMW is one OEM that did approve of splicing however it must be soldered and covered with approved watertight shrink tubing. The connection you have made really concerns me for your safety.

Anything under 500mV is very good.

Sure, either pull the fuel pump fuse or the fuel pump relay, either one will prevent the car from starting. I agree with JFP, however here is a tip / trick of the trade I use so I dont have to pull the fuse or relay. If you have a good DVOM you can use the Min Max feature. Instead if a step by step writeup please watch the video to explain how this works in detail. Using Min Max is an invaluable tool for all diagnostic testing.

Voltage drop testing is the best way to find the problem because it is dynamic. Your testing the actual components with out disturbing any connections that might be the issue. As a factory trained tech I use voltage drop testing as one of my first diagnostic testing strategy's. Today's cars have up to 75 + computer modules on board and most of our problems come form bad grounds and or resistance connecting circuits.The problem with only using an Ohm meter is your not testing the circuit under load so is might ohm out as good but will fail when you put a load on it. Diagnostic Auto Lab

Thank you for the info. Best, Bing

Hi Loren, Thanks for the heads up I pulled it from PET 7.3 thinking it would not been superseded yet.

Hi, After going though PET and based on the info you posted 2004 Cayenne S 4.5L I am sure this is your part # 999-192-380-50. Please check the exploded view in the PDF if you don't think its a match please give me the VIN# and I will re post. 2004 Cayenne S 4.5L.pdf

Hi Jason, You said, No idle issues No performance issues? So your 996 is running fine? it's not running rich? or your just getting the P1123 code? from the latest o2 upstream sensors PDF you posted the DME has no fuel control. the readings look worse that your first post. I did find a TSB on your car for o2sensors see this link below. Also the next time you test the down stream o2 sensors please change the values from Ohms to mV. Thank you in advance. http://www.renntech.org/forums/index.php?app=downloads&module=display&section=download&do=confirm_download&id=165

Hi, It's a serpentine belt. Please post your VIN# so I can give you the correct part number.

Hi Jason, We are going to need more info so I can try to walk you through the steps to solve your issue. Please fill out the two work sheets and post the info. This weekend when you use your scan tool please check the following RPM, ECT, TPS, MAF, IAT, both upstream o2 sensors and downstream o2 sensors. The car needs to be at operating temp & closed loop, the motor should be ran up to 2000 RPMs. Please in post this info too. You will need a fuel pressure gauge a hand vacuum pump & vacuum gauge. FYI the only real way to test for vacuum leaks is with a smoke machine and that costs lots of $$$$. Customer Concerns.pdf Drivability Work sheet.pdf

I know it can be confusing how these systems work. It is the opposite of what we might think. The o2 sensor reads the gas just before the cat and sends a signal to the DME. If it has low voltage the DME sees that as the motor is too lean. The DME now commands the injectors to add more fuel by making pulse width longer. That's why your car is running rich. Hope this helps. Bing Diagnostic Auto Lab

Voltage drop testing is the best way to find the problem because it is dynamic. Your testing the actual components with out disturbing any connections that might be the issue. As a factory trained tech I use voltage drop testing as one of my first diagnostic testing strategy's. Today's cars have up to 75 + computer modules on board and most of our problems come form bad grounds and or resistance connecting circuits.The problem with only using an Ohm meter is your not testing the circuit under load so is might ohm out as good but will fail when you put a load on it. I have attached one more video that shows how to pinpoint with voltage drop testing. Hope this helps. BingDiagnostic Auto Lab

Hi dphatch, You need to do a voltage drop test on both the positive side and the negative of the circuit using a DVOM. I found a video that will make it simple to understand however its not on a Porsche :). As the saying goes a picture is worth a thousand words. Hope this helps.