95 Grand Am no ALDL WON'T FLASH

[jenniesdog]

my 95 G.AM. is'nt flashing trouble codes , I've check for ground or going to ground problems, seem ok , swaped out ecm and cal with no change, lite is on in ignition on position and goes out when start engine then comes on will come on in few seconds and stay on. but when trying to obtain codes by normal grounding of a/b at aldl ( it's a 12 pin ) it wont flash. ( need some expertise on this one) also, yeh I know 2.3 quad (known for problems) but I like a good challenge , when at idle (somewhat smooth) and press the accel it cuts out real bad ( new plugs and coil and housing appear ok ) just noticed today the first part downside of exhaust manifold (resinator or cat con ? ) seems to glow red hot at device end going towards another device then the muffler., possible restriction , any clues would be great , I'm just a old shade tree that tries to stay current and keep my GM running smooth.
Thanks The Dog

[xeroinfinity]

Welcome to AF Dog!

You'll need a scann tool most likly for your 95'.

If the down pipe is glowing befor the cat converter then it is likly its pluged.
Does it lose performance too when it glowing?

[jenniesdog]

Originally Posted by xeroinfinity

Welcome to AF Dog!

You'll need a scann tool most likly for your 95'.

If the down pipe is glowing befor the cat converter then it is likly its pluged.
Does it lose performance too when it glowing?

Yes it does seem to loose performance, I'll find out today if something is restricted, I've never seen one glow red just at the outlet end of device the other round part, pipe and muffler don't glow, anyway , big thanks for the welcome, still need some brainstorming on the ALDL "SES" THAT WONT FLASH ANY CODES. also may get a chance to share some past experience , been turning wrenches " mostly GM " for over 25yrs. I'll do a Ford for certain friends. thanks for the reply

[xeroinfinity]

Try this thread on ODB.
I've posted the ODB I on the bottom portion(its a big page).
ODB trouble codes


Some models of GA's are not able to set the diagnostics with the a-b wire trick. They need scanned by a scan tool and its possibly dealer time.

but the ses could be a O2 sensor, throwing the code bacause your cat is bad, and giving a high output reading.
If thats the prob and you fix it , after the battery is disconnected for a while(30-60min) the code may go away.

Hope that helps