2 replies to this topic

[code33]

Hi everyone,

Picked up an 850 Turbo about a month ago with 85k miles. Replaced the motor oil with Mobil 1, did a tranny flush, and ran Seafoam treatment. Also, changed the serpentine belt and installed a boost gauge.

Some service history:
60k mi.: Front o2 sensor
62k mi.: Ignition coil, fuel pressure regulator, dist. cap/rotor/wires
65k mi.: Timing belt, shift lever lockout switch, & coolant cap
67k mi.: Air mass sensor & turbo drain pipe seal
84k mi.: Both front CV axles & upper engine mount bushing

I cleared a long list of codes on the computer. The only one that keeps on coming back is 443 (Three Way Cat efficiency); it doesn't throw the check engine light. I can tell when the code is present when turbo boost will not go above 6psi. Once the computer is reset, I can boost at 9.6psi for a few days until the code comes back. Does it appear that the cat needs to be replaced?

Perhaps the results to the emissions tests may help:

Feb 2006
15 mph; 1725 rpm
%CO2 MEAS 14.8; %O2 MEAS .1
HC (PPM): MAX 84; AVG 21; MEAS 23
CO (%): MAX .49; AVG .06; MEAS .22
NO (PPM): MAX 692; AVG 150; MEAS 238

25 mph; 1717 rpm
%CO2 MEAS 14.8; %O2 MEAS .1
HC (PPM): MAX 49; AVG 13; MEAS 13
CO (%): MAX .46; AVG .05; MEAS .19
NO (PPM): MAX 711; AVG 136; MEAS 305

Jan 2005
15 mph; 1767 rpm
%CO2 MEAS 15.10; %O2 MEAS .11
HC (PPM): MAX 84; AVG 21; MEAS 59
CO (%): MAX .49; AVG .06; MEAS .21
NO (PPM): MAX 692; AVG 150; MEAS 359

25 mph; 1739 rpm
%CO2 MEAS 15.00; %O2 MEAS .07
HC (PPM): MAX 49; AVG 13; MEAS 33
CO (%): MAX .46; AVG .05; MEAS .20
NO (PPM): MAX 711; AVG 136; MEAS 321



Thanks in advance!

Edited by code33, 14 March 2006 - 07:24 PM.

[James100]

If you never put a rear O2 sensor in I would look into that before I replaced the cat.....If yours doesnt smell or rattle I would replace the rear O2 but I would also look at the front to see if it was contaminated somehow.....You can tell by the color if they are working correctly.......I was just doing a search on the Cat smell and you can read these:
Bad Cat
More on Bad Cats

I had the code your talking about(443) and the slow response O2 sensor(435) code and they went away after I changed the front O2 sensor....The rated life span is 100K but it can get killed by contamination earlier.....

Edited by James100, 15 March 2006 - 09:03 PM.

[code33]

I'm checking with the previous owner to see if he recalls the rear O2 sensor ever being replaced. I have a feeling it has not been.

The service records show a 443 and 435; that was when the front O2 sensor was replaced.

If you never put a rear O2 sensor in I would look into that before I replaced the cat.....If yours doesnt smell or rattle I would replace the rear O2 but I would also look at the front to see if it was contaminated somehow.....You can tell by the color if they are working correctly.......I was just doing a search on the Cat smell and you can read these:
Bad Cat
More on Bad Cats

I had the code your talking about(443) and the slow response O2 sensor(435) code and they went away after I changed the front O2 sensor....The rated life span is 100K but it can get killed by contamination earlier.....