I think the topic pretty much says it all. what do i have to do to get my computer to go along and be happy without smog equipment? can i ditch the air pump and all that (i know there are atleast two connectors for that) and the charcoal cannister and some other stuff without throwing a ton of codes? if so, how? Can they all be tricked like is done with o2 sims? I haven't done it yet, i'm new to EFI and i'm swapping an lt1 intake with a tpi computer/harness from an 85 'roc onto a carbed 85 with absolutely no computer. Also, will i trip any codes by not connecting the 4 wire connector to the trans (pretty sure it's tcc lockup and/or vss), because i'm going to a th350...thanks in advance, i appreciate it.

 

You can remove the air pump and charcoal canister and your ECM should not throw any codes. Many have done this and I don't know of anyone who has had troublecodes as a result. The only way to properly remove those from the ECM is to have a custom PROM that has the charcoal canister (purge soleniod) and air pump disabled.

Let me be the first to say that you should consider using a newer wiring harness and ECM. The 85 is a poor design and not recommended by anyone on this board. The 85 ECM is unique and not swapable with any other year. You should be able to search this board and find more info about why not to use the 85 ECM.

I'm not sure what to say about the tranny.

 

Disconnecting the two air pump plugs will not cause any codes. The ECM receives no feedback from these. It won't know they are not plugged in. The canister I can't tell you about, mine is still hooked up. The one thing that will cause a code is the EGR valve. If you don't have an EGR valve it must be disabled in the PROM or you WILL get a trouble light in about 15-20 minutes.

 

I'll echo what S10wildside said. The 85 ECM is garbage. Last summer I converted from the stock 85 ECM & harness to the 86-89 style. It was an easy swap and my results were profound. There's another thread right near the top of this forum that has more info on it.

Nevermind. You're the one that started the thread I'm talking about. I need a vacation.

 

If I was to disable my AIR and charcoal canister (juck out or ebay)
would that throw anycodes? I've got a '91 by the way.

 

I'll repeat what I posted above
"You can remove the air pump and charcoal canister and your ECM should not throw any codes."

If you "disable" them (requires prom editing), the ECM will ignore that functionality. If you "remove" them, the ECM will not throw any codes, but WILL think they are still there.

 

Let me put it this way- I have NO smog equipment on my 1971 Camaro and the ECM doesn't know the difference.

 

What about the oxygen sensor? I removed mine due to a header install and now I get the SES light after a few minutes of driving.

 

You can not remove the oxygen sensor....it is not optional. Your car starts up in "Open Loop" and stays there for a few minutes until the oxygen sensor warms up and the time delay has passed. Your vehicle then goes into "Closed Loop", where your Air/Fuel ratio is monitored by the oxygen sensor and adjusted accordingly. The oxygen sensor is the most critical sensor for Closed Loop. Put it back in.

 

Where should I put it ? In the header collector (long tubes) or the exhaust pipe after the collector?

 

Typically those who are using long tube headers are mounting the sensors back much further than the stock position...and as a result convert to a heated oxygen sensor. That way the ECM will enter closed loop quicker.

I don't own a ThirdGen, so I'm not familiar with the header lengths and such. I'd ask around because I can't say for sure where the sensor should be put in your case.

Having said that, I am a ThirdGen enthusiast in that I'm running my S10 with a ThirdGen engine and electronics.

 

If you're running headers, you'll likely need to get a 3-wire heated O2 sensor. The O2 sensor must be at a particularly high temperature in order to send the ECM into closed loop operation. When I did my headers, I put the sensors in the collectors and they were not getting sufficiently hot on their own and the ECM would go in and out of closed loop- especially at idle speeds. With the 3-wire, you would have to add a +12V and a ground wire to the signal wire that is currently going to your sensor- not too tough to do.

 

Thanks S10Wildside you da man.