vdocad

Good afternoon everyone,

Last week I purchased my first Chevy. It is a 2005 shuttle bus built on a Chevy Express 3500 van chassis. I knew the engine light was on when I bought it. Also the previous owner had just replaced both catalytic converters which had been stolen. The van runs fine, idle speed is fine too, no hesitation at either low or high speed.
When I checked the codes this is what I got in this order: 0053, 0054, 0059, 0060, 0135, 0141, 0154, 0155, 0161, all related to the Ho2 heater resistance or o2 sensors. Then, the last code is 0300, multiple cylinder misfires.
I checked the O2 fuses, fine, the wiring at the sensors, fine, disconnected and reconnected all of them but do not know what else to check. In doing that I found the hose in the picture disconnected, it seems to come from above the transmission but I can't see where exactly.
Looked around for an obvious location to connect it but found none. Not sure this is related to the codes or not... Any ideas where it goes?
About the codes, should I replace plugs, wires and coils first and then the O2 sensors if the problem persists or the other way around? I realize that one situation could trigger the other but not sure where to start.
Any input will be greatly appreciated

mountainmanjoe

There should be letters in these codes. The first character is usually P, C, U, etc. Could you please post the entire code, and definition? Thanks.

oldchevy

Welcome from Florida. You are getting codes from all 4 02 sensors. That would lead me to think that when the catalytic convertors were stolen there could have been some damage done to the wiring harness. Check that carefully and I would check the sensors before changing plugs, wires, etc. That hose looks like it could be the drain for the AC system. Good Luck!

William Kisselstein

Was the bus driven without the converters in place?

Clear the codes, see if they come back.

vdocad

Thanks for the reply. Actually the bus was rarely driven, it belonged to a business that transported handicapped people from point a to point b, but business was really bad. It passed inspection last October when they replaced the catalytics. I have cleared the codes several times but they come back as the engine warms up. I am not driving it until I figure this out...

vdocad

Thanks! The wiring harness on all 4 sensors looks great. Is there a way to test the sensors?

vdocad

Given the lack of ideas I went ahead and ordered the o2 sensors and we will see what happens...

TXLeadfoot

The hose vents the transmission from the top. I have the same thing on my 04. Looks like an afterthought!

vdocad

Thanks for your input!

vdocad

Update. After a long week waiting for parts to arrive, I have replaced air filter, O2 sensors(4), plugs and wires. The error codes went down from 10 to 3. Now I have codes P0141, P0161 and P0300.
I borrowed a Centech OBDII scanner and recorded the data on the pictures. Not sure what to expect so I would appreciate your comments.

PS: I used a stethoscope looking thing to listen to the injectors at work. All on the driver side tic ok but I noticed the one on the left closest to the cabin makes no sound... Need to check the other ones as well but they are kind of hard to get to.