P0430 Code - 2001 Boxster

[AtlantaBoxster]

1) Moved O2 sensors from one side to the other - Still get P0430 code.
2) Just cleaned MAF sensor yesterday - waiting to see if code will pop up again. Never know how long it takes. Was replaced 2 years ago. Looked prestine.
3) Recently changed air/oil seperator.

thstone

I am not sure how I could check for exhaust or intake leak - Will google that. I 'm thinking I need a smoke generator of some sort though.

paulv - I must say you've thrown me for a loop in many of your diag suggestions.

You obviously have much more experience than I do. Are the items you detail relatively easy to do once I understand what they mean?

[paulv]

Originally Posted by AtlantaBoxster

1) Moved O2 sensors from one side to the other - Still get P0430 code.
2) Just cleaned MAF sensor yesterday - waiting to see if code will pop up again. Never know how long it takes. Was replaced 2 years ago. Looked prestine.
3) Recently changed air/oil seperator.

thstone

I am not sure how I could check for exhaust or intake leak - Will google that. I 'm thinking I need a smoke generator of some sort though.

paulv - I must say you've thrown me for a loop in many of your diag suggestions.

You obviously have much more experience than I do. Are the items you detail relatively easy to do once I understand what they mean?

The P0430 most likely a 2 drive cycle code which means that you would have to drive twice (shutting it down, cooling off, start up again and drive a mix of idle and cruising) to see if the CEL will come on again with the same code.

Are the two aft O2 sensors still swapped?

And yes, the best way to find a leak is with a smoke machine. Any place (the cat convertor, near the O2 sensor, etc.) that will allow for air to come in will throw the reading of the aft O2 sensor off. Also check the wiring harness/connector to the O2 sensor.

From reading the code, did you get any freeze frame data? If you had it read at a parts shop, go back and see if the scanner they use provides FF data -- if so, get that info and post here.

Regards,
paul..

[AtlantaBoxster]

paulv

Yes, the O2 sensors are still swapped. I did not move them back. Since I switched all the O2 sensors, I did remove and put back the harness. If the harness was not seated properly, would I get a P0430 code or something else?

Just ordered this little jobby. Will see how well it works. Only $38 bucks, worth the risk. Seemed fairly decent reviews.

I'll let you know the results after I test it.

http://www.amazon.com/Crescent-OBD2-Multi-Protocol-Diagnostic-Scanner/dp/B001MT0XPK

[Jager]

Per Paulv's earlier post that listed possible causes, don't ignore the O2 sensor in front of the cat.

Jager

[paulv]

Originally Posted by AtlantaBoxster

paulv

Yes, the O2 sensors are still swapped. I did not move them back. Since I switched all the O2 sensors, I did remove and put back the harness. If the harness was not seated properly, would I get a P0430 code or something else?

Just ordered this little jobby. Will see how well it works. Only $38 bucks, worth the risk. Seemed fairly decent reviews.

I'll let you know the results after I test it.

http://www.amazon.com/Crescent-OBD2-Multi-Protocol-Diagnostic-Scanner/dp/B001MT0XPK

O2 sensors send signals back to the DME module. If the DME doesn't receive a [proper] signal, then a code will be generated. The only reason that there's a rear O2 sensor is to measure the cat conv's efficiency (under OBD2, not part of OBD1) -- the efficiency is the measure of how well the cat conv stores oxygen. Typically, the DME will look at the signals from both the fore and aft O2 sensors in order to determine if the aft O2 sensor is telling the "truth" -- thus, this is what Jager was talking about and is also in the diagnosis conditions I posted earlier.

As O2 sensors age, they get "lazy" -- which means that they don't switch as fast as they used to -- this would also generate the P0430 code.

If you have access to a graphing multimeter (or preferably an oscilloscope) you can watch the voltage signal coming out of the O2 sensor (and compare both banks) to isolate whether the O2 sensor is on the borderline of failing or it it's something else.

Also, I don't know if your year model has an O2 sensor as the fore sensor or if it has an air/fuel ratio sensor (aka: wideband O2 sensor) -- these don't have a switching voltage but they generate a current that changes polarity whether the mixture is rich or lean and stay at zero when the mixture is at the proper 14.7:1 (air to fuel). Some scan tools will convert this current to a voltage so it can be viewed easier, but not all scan tools do this.

Also, send me a PM with your email so I can send you the diags document (where I got the info to post earlier) and a DIY tutorial from a company that makes scan tools -- it's a nice intro to all this stuff. Can't post either here -- the diags doc is copyrighted and the DIY tutorial is too large.

What year is your car? I'll check to see if there's a TSB out on this issue.

Regards,
paul...

[AtlantaBoxster]

Thank you Jager.

Paulv, I sent you a pm.

[AtlantaBoxster]

I want to thank you all for helping me out on this one. The last thing I did was a simple and less than $7 fix vs. the prescribed dealer price of $1800 for a new cat (even though I found a 400 cell after market for $450 delivered).

After switching the O2 sensors from one side to the other and still getting the same pesky P0430 code, my next step was to clean the MAF sensor.

Very simple process. I had forgoteen to buy the right Torx tool and therefore used a vise grip to remove the two screws. Only cost was some time and the bottle of electronic cleaner I picked up at the local auto parts store.

Have run the car over 300 miles without check engine light coming back on. Went to get emmisions done today and passed!

Perfect and thanks again.

[deptotpr]

I had the same thing. Engine Light diagnosis code # P0430.
I stopped at Mobil for gas twice, and had a three hour drive, and ran it like it was stolen. Light came off. I am going to dump a bottle of techron too, why not!?

"Porsches are meant to be driven not polished"

The shop only sees mine from a back of a tow truck.....

No affiliation, just making my point
S•CAR•GO Racing