TheExaminer

I understand what it does, converts CO to CO2, but what is the performance consequence of removing it besides failing emissions? Would it screw with the cat and mess it up? Would the ECM start panicking and throwing codes? I have the four AIR ports in each header, and may have to do a head gasket job soon. The bolts look decent, but I'm really hoping they don't sheer off when I take them off the header.

8Mike9

If I recall, air is pushed into the cat to assist with "burning" unspent fuel.

I see no performance increase/decrease, but possible early demise of the cat if you were running on the rich side.

TheExaminer

Yeah, that's about what I figured. What about guys that take air off? Are they getting more modern cats that aren't as sensitive to it then?

Base91

iTrader: (1)

Th performance gain comes from removing a small load from the engine which no longer needs to turn the pump. If the engine is in good shape I don't think it would harm the cat. Removing the cat also may give a small gain by removing an exhaust restriction. Anyone know what hp the AIR pump actually uses? The biggest benefit may be the extra room around the engine.

paulo57509

The air injection system injects air into the exhaust manifolds. This extra air helps burn excess fuel remaining in the exhaust gases which helps reduce hydrocarbons. Burn off of excess fuel has to happen before it reaches the catalytic converter.

The air injection system also injects air in between the reduction and oxidation catalysts inside the catalytic converter. Injecting air into the converter helps it heat up quicker and also helps increases the efficiency of the oxidation catalyst. It does not help burn off excess fuel in the converter. It does this in the intake manifolds. Excess fuel in the converter will quickly kill the catalysts.

Also, the air injection system does not convert CO to CO2.

TheExaminer

Really? I thought I read that one of the functions was to convert CO to CO2 by injecting outside air into the exhaust manifolds? I read it on the internet, it has to be true.....

TheExaminer

I also wish I had all the exact facts and figures, that's part of why I started this thread. Having that extra room in the engine compartment is gold.

Damon

The Air Injection system does NOT convert CO to CO2 (at least not directly). It's main function is to lower HC emissions (unburnt fuel). It helps most on a COLD motor, first start, but it also helps the cat "light off" faster and STAY "lit off" at low engine load, idle, etc. I'm no expert but the info posted by Paulo sounds right to my modest level of understanding.

Real world: you can safely remove the system COMPLETELY if you don't care about emissions and don't have to pass a visual emissions equipment inspection. The ECM does not monitor it's functioning AT ALL.

TheExaminer

Ok thx, that makes sense. I probably won't remove mine just yet because I'm sort of a stickler for keeping things stock as much as possible. The main reason I'd want to get rid of it is to have more room to work in the engine bay. But, I'm gonna have to unbolt those babies if I have to do a head gasket job.

samiam91RS

what would happen if you have the AIR tubes capped off? i did an intake swap and didn't need to worry about emissions, soooooo i capped off the AIR tubes. I'm having trouble timing my engine and the reason why I'm asking is because either that is giving me issues orrrr its timing.

TheExaminer

Did you get the distributor indexed accurately as you were pulling it out? This is one thing I'm going to have to watch for if I have to pull my heads. That would knock your timing a little off. I can't imagine AIR has any connection to timing, as it works after combustion has taken place. The only connection between timing and an intake change that I can think of is a distributor that's a little off kilter from being moved slightly. But, I know about enough to be dangerous, someone else may know something more.

Base91

iTrader: (1)

AIR has nothing to do with anything other than injecting extra oxygen into the exhaust to help reduce measured emissions. If injected before the O2 sensor it's a factor that the ecm would take into account.

samiam91RS

i only asked because in another thread i was told it can be timing or vacc leak.

I did mark the timing before i pulled out, but when i dropped the distributor back in, it wasn't seated properly on the oil pin thing. sooo when i went to set valve lash i started turning the crank and well, you know..its a mystery now.

TheExaminer

Kind of sounds like you answered your own question there then. If the cam moved in relation to the dist, then that would screw with your timing. How to fix that is a little beyond my level right at the moment. I have a lot to learn myself!

Zane M

iTrader: (1)

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At this point, I would suggest you turn the engine by hand until you get the #1 cylinder to TDC, and restab the distributor.

samiam91RS

I did that about 3 times already. This is where im stuck at

https://www.thirdgen.org/forums/tech-general-engine/706920-swapped-intakes-motor-wont.html