Has anyone replaced the OEM air box and Air Mass Meter to a after market kit for an 1987 4runner with EFI? Does this affect the computer? What are the good kits? Also have anyone played with these power chips that I see on ebay? Do they work?

Thanks ahead of time!!

Well, you need to remember that the whole EFI is a system, and it's not like there's a big cork in any particular spot that, once removed, suddenly frees up a whole lot of power. Instead, there are a lot of things you can do to make the motor breathe better, and once it breathes better, it will generaly make more power. An open element air filter will help; a header and 2.25" exhaust will help; a better cam will help. You can do all of these things and not need to adjust the AFM by more than a click or two.

Once you start raising compression, porting the head, moving to more radical cam designs, these start to affect the EFI more and bring it farther away from the stock values for fuel and spark. More adjustment will be necessary with these sorts of modifications.

Actually replacing the AFM on a 1987 22RE (or RTE) is much more of a project, and not worth the effort unless you are already exceeding the airflow capabilities of the stock unit, which is capable of flowing enough air to support in excess of 170 rwhp.

-Jeff