pilot996

Hello,
Been getting fault codes p0420/P0430(cat. conv. eff. bank 1 and 2) every few weeks. I've been clearing them with Durametric, but they come back eventually. I've got k24/26's, 5 bar, flashed ECU and 200 cell 70mm Speedtech exhaust.

Any ideas? Both codes show up together. Am I incorrect to expect a bad 02 sensor would trigger an individual code, bank 1 or bank 2, but not necessarily together. Why are they always triggered together?

Thanks in advance for any insight,
DW

Kevin

Go to this link and read what the manufacture has said with regards to the CEL and CAT efficiency.

http://cgi.ebay.com/ebaymotors/Porsc...Q5fAccessories

Call or email Maxspeed and ask if you can get his newer exhaust with the 200 cell cats. More cells per inch will increase the efficiency, but will also increase backpressure. Another option is to cut your old cats off and install "larger" diameter cats to increase the surface area>CAT efficiency.

TT Surgeon

It's the exhaust as kevin mentioned.

Kevin

http://www.maxspeed-motorsports.com/cel.html

Article applies to the 996TT.

The bottom line is you need larger diameter cats, or same diameter but longer in length to scrub the exhaust>More surface area.

pilot996

Thanks....Am I assuming correct that the exhaust from maxspeed-motorsports and Speedtech are the exact same exhaust, just sold under a diff. name? They look exactly the same.

Kevin

Yes, you can read my statement in post #21.

https://rennlist.com/forums/996-turb...t-again-2.html

Macster

Not likely both O2 sensors went bad. More likely is converters are simply not peforming up to par. The error arises cause the converters are unable to store oxygen from the excessive oxygen in a lean phase for use in the rich phase. That is the engine controller slightly varies the air/fuel mixture from too lean to too rich -- we're talking just a tiny bit on either side of stiochoimetric -- and the converters are expected to be able when excess oxygen present to capture this and then use it when there is too little oxygen in the exhaust stream.

The O2 sensors after the converters are signaling this storage of oxygen is not happening.

The converters are probably not hot enough or if they were working fine for a while have probably lost enough catalytic material that there is not enough left to storage sufficient oxygen. The #2 O2 sensors begin to "follow" the #1 O2 sensors which cycle between 0.1 volts and 0.7 volts as the engine controller cycles between rich and lean air/fuel mixtures.

You might be able to "resurrect" the converters using a treatment or two of Techron per instructions on the bottle.

The idea is the Techron will remove fuel injector, valve, combustion chamber and possibly even O2 sensor and even converter deposits. By doing this the combustion process improves and the converters receive higher quality exhaust gases.

My 02 Boxster has been emitting a P0430 now for several years, with the error going away in warmer weather and reappearing in colder weather. The coverter is just wearing out. After 226K miles I would think so. However, I note the other original converter has never triggered on error code.

Sincerely,

Macster.