91 chevy throttle body covered completely still runs. Intake gaskets maybe?

[94chevc1500]

Hello all. Finally got my truck out for a 200 mile drive. Check engine light kept going on and off through out trip and finally stayed on coming home. Codes 42 44 45 popped up. 42 was from my new distributor install. 44 and 45 was o2 sensor to lean and to rich so I sprayed brake clean around the tb spacer around the back and the intake gaskets. No change in idle. I covered the tb completely to see if I could hear where the vacuum leak could be coming from. It still ran normal covered in thick rags and my hands on top. Also I plugged the pcv just to be sure. Still ran normal. Could it be an internal vacuum leak?

 

[fancyTBI]

How old is the O2 sensor? They get lazy. What engine?

Always start with year, make, model when asking for help. I assume is a ‘94 C1500.

 

[evilunclegrimace]

How old is the O2 sensor? They get lazy. What engine?

Always start with year, make, model when asking for help. I assume is a ‘94 C1500.

It says '91 in his opening

 

[fancyTBI]

It says '91 in his opening

I don’t have time to read! Thanks for pointing that out. Usually forget the title by the time I get to the thread.

 

[GoToGuy]

You know, unless I've got a runaway diesel, I highly discourage you from placing anything in the TBI throat, intake area. The chances of something going into the engine, not good.
Inspect closely, all vacuum lines, hoses, new PCV valves are cheap, vacuum booster hose, cracked elbows.
The emissions sticker on the radiator shows all vacuum line routing. If there's no reaction where your spraying, then that's not problem.

 

[scott2093]

Sounds like there is a back story to this thread by the way it was started. ?idk
here are some screenshots of the codes from emissions manual.....

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[Sean Buick 76]

Look for a leak by poking a small un lit propane torch around the intake. If it revs up it’s leaking.

 

[94chevc1500]

Sorry to be late on the reply I ended up using brake cleaner on the intake manifold gaskets and it was in the middle between 4 and 6 only under load. Replaced them and now it's good. Thank you

 

[Sean Buick 76]

Sorry to be late on the reply I ended up using brake cleaner on the intake manifold gaskets and it was in the middle between 4 and 6 only under load. Replaced them and now it's good. Thank you

Awesome

 

[Schurkey]

I sprayed brake clean around the tb spacer

Look for a leak by poking a small un lit propane torch around the intake. If it revs up it’s leaking.

I ended up using brake cleaner on the intake manifold gaskets

DO NOT use "brake cleaner" to check for vacuum leaks.
1. Some of it is not flammable. Useless for checking for leaks
2. Some of it degenerates into deadly Phosgene gas when burned. Can truly FUUK YOU UP if you breathe it. Maybe kill you.

An unlit propane torch can work. I've done that. I actually prefer aerosol carburetor cleaner.

But NOT AEROSOL BRAKE CLEANER.