Quote:
Originally posted by gofstbuick
If you have to pass a visual inspection, then removal of the plumbing leading up to the AIR port on the catalyst may cause a visual failure. One of the functions of the AIR system (during warm up) is to get the catalyst to light off, by adding oxygen to get the catalyst up to operating temps faster. Thus allowing closed loop operations sooner (bear in mind that closed loop is really a funtion of coolant temps and O2 switching).
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Sir, you are a wealth of information!
I am curious about one thing on air injection and manual trans. It appears that all manual trans applications use air injection whereas the automatics may or may not.
I understand what it does but why does a manual trans change that? On a 3.4L DOHC, the injection only runs on a cold start. I figure the cat would heat up the same as it would with an automatic. The service manual implies that the injection stops after the temps come up and it's not used after that. I notice the F/Y body use the injection on both auto and manual and that some ECM's have provisions for it but don't use it on the automatics (3800 V6 is a good example).
I'm not talking about the older carburated cars. I understand the need there. It's as if the air pump is a last ditch effort to keep the cat lit but why would it be different for a manual over an automatic?