Service Engine Soon light -- what say you? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


2000-2005 Discuss your 2000-2005 Bonneville SE, SLE, and SSEi Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 10-30-2007, 04:36 PM   #1
Junior Member
Thread Starter
 
Join Date: Sep 2002
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
jwakamud is on a distinguished road
Default Service Engine Soon light -- what say you?

my SES light came on today, so i took it to autozone to have them run the codes for me. heres what it says:


Quote:
The PCM has determined that the catalyst system efficiency for bank 1 is below threshold for the current engine conditions. (Bank 1 identifies the location of cylinder 1, while bank 2 identifies the cylinders on the opposite bank)

Definition: Catalyst efficiency low - bank 1
Explanation: The oxygen sensors monitor the catalytic converters ability to store oxygen.
Probable Causes:
1. Catalytic Converter defective (failure possibly due to #2, #3, or #4)
2, Engine misfire or running condition
3. Large vacuum leak
4. Engine oil leakage into exhaust-valve guide seals, piston rings
so whats the damage, o' purveyors of all things L67?
jwakamud is offline   Reply With Quote
Old 10-30-2007, 05:29 PM   #2
Senior Member
True Car Nut
 
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Thanks: 0
Thanked 0 Times in 0 Posts
Rogue is on a distinguished road
Default

Since you dont list the actual code I will assume its just a rear 02 code.

Either bad rear oxy sensor or bat cat (or no cat)
Rogue is offline   Reply With Quote
Old 10-30-2007, 05:30 PM   #3
Junior Member
Thread Starter
 
Join Date: Sep 2002
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
jwakamud is on a distinguished road
Default

P0420, i guess thats the code? sorry.
jwakamud is offline   Reply With Quote
Old 10-30-2007, 10:03 PM   #4
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Bank one is the front O2. I would check the connection and ensure no plug wires are resting on the wiring to it.

I checked the FSM. As Todd mentioned..it'* looking at the difference between what the front and rear O2'* are reading. This code directly relates to how well the catalytic is working by looking at the difference between the front and rear sensors.
BillBoost37 is offline   Reply With Quote
Old 10-30-2007, 11:37 PM   #5
Senior Member
Posts like a Camaro
 
Join Date: Jan 2004
Location: Aurora, Illinois
Posts: 922
Thanks: 0
Thanked 0 Times in 0 Posts
1994se is on a distinguished road
Default

I get it once the car is warmed up and then idles at a stop light for awhile, maybe twice a week. I just clear it with my aeroforce and keep going. I have a brand new 3" highflow magnaflow cat so i don't know what the 02 sensors deal is.
1994se is offline   Reply With Quote
Old 10-31-2007, 09:29 AM   #6
Senior Member
True Car Nut
 
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Thanks: 0
Thanked 0 Times in 0 Posts
Rogue is on a distinguished road
Default

Quote:
Originally Posted by BillBoost37
Bank one is the front O2. I would check the connection and ensure no plug wires are resting on the wiring to it.

I checked the FSM. As Todd mentioned..it'* looking at the difference between what the front and rear O2'* are reading. This code directly relates to how well the catalytic is working by looking at the difference between the front and rear sensors.
Actually Bank 1 is both sensors, sensor 1 is the front sensor 2 is the rear. The 420 code is a rear 02 code.
Rogue is offline   Reply With Quote
Old 10-31-2007, 09:31 AM   #7
Senior Member
True Car Nut
 
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Thanks: 0
Thanked 0 Times in 0 Posts
Rogue is on a distinguished road
Default

Quote:
Originally Posted by 1994se
I get it once the car is warmed up and then idles at a stop light for awhile, maybe twice a week. I just clear it with my aeroforce and keep going. I have a brand new 3" highflow magnaflow cat so i don't know what the 02 sensors deal is.
Your magnaflow cat is not working to spec for the rear 02 sensor (most aftermarket cats don't)
Rogue is offline   Reply With Quote
Old 10-31-2007, 10:43 AM   #8
Senior Member
Certified Car Nut
 
Join Date: Oct 2002
Posts: 11,307
Thanks: 0
Thanked 0 Times in 0 Posts
bonnie94ssei is on a distinguished road
Default

Which is reason to delete the rear O2 via PCM.
bonnie94ssei is offline   Reply With Quote
Old 10-31-2007, 12:52 PM   #9
Senior Member
Posts like a Camaro
 
Join Date: Jan 2004
Location: Aurora, Illinois
Posts: 922
Thanks: 0
Thanked 0 Times in 0 Posts
1994se is on a distinguished road
Default

It'* on the to do list next when i get my PCM re-flashed with higher shift points come spring.
1994se is offline   Reply With Quote
Old 10-31-2007, 12:56 PM   #10
Junior Member
Thread Starter
 
Join Date: Sep 2002
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
jwakamud is on a distinguished road
Default

so if i look at the cables and theyre fine, nothing resting on the wires,what am i looking at? bad cat, being that its stock? or could it still be one or both of the O2s?

i assume if the plug wires are resting on the cable, i can just re-route the wire and reset the code? or will it go away on its own?
jwakamud is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
got service vehicle soon light, trac off and abs light on at same time blaze420711 Pontiac 6 10-19-2014 11:54 PM
service engine soon light on. Jrios 2000-2005 8 04-13-2004 05:33 PM
Service Engine soon Light SSEimatt93 General GM Chat 8 06-09-2003 02:16 PM
Service Engine Soon Light Cheap00Bonneville 1992-1999 4 01-04-2003 10:53 PM
SERVICE ENGINE SOON LIGHT PROBLEM 94SSEgold 1992-1999 4 01-01-2003 08:47 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:57 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.