WS6 TA

I know on earlier LT1 cars removing the smog/air pump didn't set a code, and _originally_ on the later cars like my '97 it did, but I'm wondering if that is still the case since they did the recall? I know that the new setup is wired differently, has different wiring/plumbing and the PCM was reprogrammed. I also know that the vetts didn't use one, and when the b-bodies went in for the recall they just got rid of it and reprogrammed the PCM not to use it.

In my case it's a WS6 car that had different plumbing there to start with, and the redo is just a disaster/rats nest of wiring and large hoses that gets in the way of everything, they contact the back of the fans and the new, modified harness tangles into everything (primarily the ignition...) on that side of the car. Originally it actually rubbed things, but then got zip tied down in a few places to make it at least not cause problems with other things, but every time I have a reason to mess with that side of the engine compartment it has me swearing.

Sort version: the thing really gets in the way now, and since I got stuck taking it all apart putting a new waterpump in the car (there is no disconnect a hose or 2 and move it out of the way like you could originally), I'm wondering if you could just leave it out without setting a MIL or if there is some easy way of tricking the setup into thinking it's still there (if it will still set a code, what does the ECM check for to set that code?)?

Injuneer

There are two codes for the AIR system in OBD-II. One checks the AIR pump relay system. Unplugging the pump seems to set a code, unlike in OBD-I. The other code diagnostic cycles the AIR pump on and off, and looks for a change in O2 content in the exhaust.

The recall dealt with trying to stop the backflow of exhaust into the pump, which caused it to rust and sieze up, and to increase the wire size because it was too small to begin with. I'm not aware of any of these changes having an impact on the codes.

Simply have your PCM reprogrammed to eliminate the codes.

WS6 TA

Thanks Injuneer, that does answer the question.

And yea, that's the simple answer if I had some way to program it, but I don't and last I checked there really isn't anyone local to do it or that would do it for reasonable money (another reason that I still prefer messing with my 3rd gens... chip burning is cheap and easy).

That raises another question that I've been wondering about this. I know that MD emissions testing requires that there be fewer than 2 "not enough information" flags set or an MIL light automatically fails the test (well, the first time, if the car hasn't been cycled enough for something to have enough information they will tell you to come back for a retest in 2 weeks)... if something emissions related is disabled so it doesn't set a MIL any longer (for example the both air pump checks, the misfire check if you're running a big cam...) does the plug in test just not see them or do they show up as not having enough information and you would eventually fail?

Injuneer

A knowledgable programmer knows how to delete the codes, while not causing a "not ready" flag.

HardTop

Injuneer,

Who would you recommend as a knowledgable programmer, because I'm in the same boat needing to pass a plug in test...

Injuneer

Trifecta is a Supporting Vendor. Check the Supporting Vendor Index.

Many seem to like pcmforless and MadZ28 also.

HardTop

Thanks!

6speedlt1

What do you use to plug the hole in the air intake where the one of the AIR pump tubes used to connect?

Thanks

MarkW
97 Formula

Injuneer

Do you mean the nipple on the air intake duct, that the AIR pump suction hose connects to? If so, a 5/8" vacuum cap works.

WS6 TA

a 5/8" heater hose cap (help section of the auto parts store)

Sick97SS

Hate to bring up a year old thread but it's still relevant so what the hell........

I just removed all my smog pump but left the EGR alone. I havent had cats for 3 years but also hate SES lights. so my AIR pump has been in there,,,till now. I was reading HERE that you can simply
""splice a pc fan to the smog pump connecter to trick the computer to think its working.""

Any one know any more info to this. It'll be some time before i can send off the computer to get the code tuned out, and I'm a huge fan of DIY.

There gotta be SOME WAY to trick the pcm to thinking the smog pump is still there, aside from tuning it out...

shoebox

Ask yourself "How is a pc fan going to cause a change in O2 readings?"

Sick97SS

I was just hoping there was just a temporary fix such as jumping the smog connector or something. The "pc fan" idea got me all excited into thinking maybe the PCM is just looking for resistance in the AIR circuit when you start the car, the "pc fan" could be providing the same amount of resistance as the actual AIR pump? just wishful thinking?..

I have an ORY with O2 sims so the AIR system is worthless anyways. All im trying to do is avoid a SES light,,,instead of blowing $60 + daily driver downtime for another tune.

Injuneer

The guy that wrote the post you are quoting from didn't have a clue. He didn't even seem to understand the difference between the AIR and EGR systems. As Rob noted, in OBD-II the PCM cycles the pump and looks for a change in O2 sensor readings. IF the pump is not there and fully hooked up, the O2 readings won't change.

shoebox

I was trying to get you to think about what Fred said about O2 readings (maybe you did not read it). I know the pc fan was for resistance. A simple resistor could probably take care of that. With an OBD-I car, all you need is a good fuse and relay in the circuit and there will be no code. OBD-II is more discerning and harder to circumvent.