First use of the new tool...

[p m]

... on someone else's Bosch D2.

Here's the glory:
P1884
P0445
P0448
P0102 - MAF
P1590
P0340 - CPS
P0134 - O2 Bank 1/sensor 1
P0154 - O2 Bank 2/sensor 1
P0135 - O2 Bank 1/sensor 1 heater
P0155 - O2 Bank 2/sensor 1 heater
P0141 - O2 Bank 1/sensor 2 heater
P0161 - O2 Bank 2/sensor 2 heater

The truck runs well, but ridiculously rich. All O2 sensor show about 0.445V steady.

Can there be a single common reason for very rich mixture?

 

[SGaynor]

Why are the O2 heater circuits tripping a code? And lots of other code for shorted circuits.

Bad ground? Chaffed wiring? Bad ECU?

 

[discostew]

while your watching the o2 voltages give one a ground on the red black wire . What ever one is easiest for you to get at . Backprobe into the connector with a t pin and ground it with a jumper wire . see if the voltage on that sensor starts to switching.

 

[p m]

Don't know much. The owner says he's replaced one or both of upstream O2 sensors, and MAF (with something _other_ than genuine, but supposed to be right).
The combination of P0102, P1590, and P1884 points me to MAF (after learning a little about Bosch EFI), but not 100% convincing.

 

[mjbrox]

... on someone else's Bosch D2.

Here's the glory:
P1884
P0445
P0448
P0102 - MAF
P1590
P0340 - CPS
P0134 - O2 Bank 1/sensor 1
P0154 - O2 Bank 2/sensor 1
P0135 - O2 Bank 1/sensor 1 heater
P0155 - O2 Bank 2/sensor 1 heater
P0141 - O2 Bank 1/sensor 2 heater
P0161 - O2 Bank 2/sensor 2 heater

The truck runs well, but ridiculously rich. All O2 sensor show about 0.445V steady.

Can there be a single common reason for very rich mixture?

what is the coolant temp?

 

[p m]

Moderate - only ran it for a few minutes to see the time history on O2 sensors, up to about 130F. Doesn't overheat, no known history of overheating.

 

[Keanan]

Check fuse #2 in the fuse box under the hood. I'll bet $4 that it is blown.

 

[p m]

Will do.

 

[mjbrox]

I ma very new at trouble shooting this shit, but could it be running cool?

 

[Rene M]

Clean the MAF, check for good air flow through the filter and air box. Have an infer red gun? Whats the engine temp? how old is the engine temp sensor? All common causes for a rich run. whic
h can and will cost you a pair of Cats and possibly an engine as well. you are washing out the cylinder liners.

 

[Rene M]

Also a bad IAC will cause a rich run. If its been rich for a long time and your just now chasing the problem. throw all 4 O2 sensors away and start with new ones. a rich run for a prolonged period will build up fuel on the O2 sensors and burn out the heaters making a bad situation very much worse.

There is a long shot..... this is risky to say the least but i have done it for customers with thin pocket books. after cleaning the mass air flow and making sure it can breath....
take a small plastic bottle fill it water, poke a very small hole in the end cap. with the engine at full temp and the air tube disconnected from the air box... drip in water while raising the engine rpm to compensate.. DO NOT POUR WATER IN just drips that will form steam in the intake and heads before entering the cylinders. the steam will blast out any carbon in the combustion chamber, clean the plugs, and steam clean the O2 sensors even clean the cats as well but not very well.. It may clean the O2 sensors well enough for the heaters to work again. If the resistance is to high the ECM will shut down the heaters. This is a stop gap measure and will get you a clean run for a while . long enough to find out the root cause of the Rich run. The codes you have there look like this has been going on for a while. there are secondary codes which have been caused by this rich run going on to long.