2 new questions
Thread Starter
Instructor
Joined: Mar 2004
Posts: 212
Likes: 0
From: Fairfax VT
2 new questions
Hi All,
Question 1--- I have climate air on my 87. I read a process that allows the owner to diagnose certain problems with the air conditioning. The process was done on a 90 vette. It involved using the fan up and down arrows and other keys. Will this diag. process work on my 87 as well ?
Question 2---- On the header down pipes right after the bend I have two canisters. They look like cats. What are they ?
Thanks
Don
Question 1--- I have climate air on my 87. I read a process that allows the owner to diagnose certain problems with the air conditioning. The process was done on a 90 vette. It involved using the fan up and down arrows and other keys. Will this diag. process work on my 87 as well ?
Question 2---- On the header down pipes right after the bend I have two canisters. They look like cats. What are they ?
Thanks
Don
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: 2 new questions (Don in Vermont)
I can help you on question 2. Those are pre-cats. I think they were supposed to help you pass emissions before the main cat lights off or some crap. You can easily pass emissions when without them.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: 2 new questions (Don in Vermont)
I'm in the process of updating some pages on my site, so here's some HVAC diagnostics:
When the Climate Controller detects a fault, the EXT TEMP LED will flash for 60 sec at power up. To enter the debug mode, press and hold FAN ^ and EXT TEMP buttons for a Convertible or FAN ^ and REAR DEFOG for a Coupe.
Page through the diagnostic menu with the WARM (right) button and select the desired option by pressing the COOL (right) button.
Diagnostic Menu
Num Test Component ID
1 = Program number
2 = In car Thermister
3 = Ambient correction
4 = Blower number
5 = Outside temperature Thermister
6 = Feedback Potentiometer position
7 = Calculated Door position
8 = System Fault
9 = Software Version number
Indeed those are pre-cats to aid the inefficient main cat. These days a Random Technology 3-stage cat is a 49-state legal replacement for those pre-cats and the stock main cat. Installing a 2 1/2" mandrel-bent front Y with the new cat is a great way to release "hidden" HP.
When the Climate Controller detects a fault, the EXT TEMP LED will flash for 60 sec at power up. To enter the debug mode, press and hold FAN ^ and EXT TEMP buttons for a Convertible or FAN ^ and REAR DEFOG for a Coupe.
Page through the diagnostic menu with the WARM (right) button and select the desired option by pressing the COOL (right) button.
Diagnostic Menu
Num Test Component ID
1 = Program number
2 = In car Thermister
3 = Ambient correction
4 = Blower number
5 = Outside temperature Thermister
6 = Feedback Potentiometer position
7 = Calculated Door position
8 = System Fault
9 = Software Version number
Indeed those are pre-cats to aid the inefficient main cat. These days a Random Technology 3-stage cat is a 49-state legal replacement for those pre-cats and the stock main cat. Installing a 2 1/2" mandrel-bent front Y with the new cat is a great way to release "hidden" HP.
