Installed the 1zz throttle body -

[tk-421]

Originally Posted by AlainMikli

I wonder how the stock(1nz) intake tube can bolt onto 1zz TB since the 1zz has bigger outer diameter.

It can, but you need to increase the inner tube diameter a little. I used a dremel with a filing bit and it came out great.

[tk-421]

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

[white_rice]

Originally Posted by tk-421

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

Thank you. So you just swapped the chip, but didn't touch that idle screw at all?

[white_rice]

Originally Posted by tk-421

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

Also what size screws did you use to replace the existing rivets?

[tk-421]

Originally Posted by white_rice

Too many variables here. Suppose I will start with the chip swap and move along from there.

The chip swap should be enough to fix it. I'm 99% sure the idle screw just helps nudge the idle up or down in the RPM range, but not enough to throw a CEL.
Just make sure the battery has been disconnected for a while. Otherwise you won't be able to tell for sure if it's due to the ECU storing previous settings or not.

Originally Posted by white_rice

Also what size screws did you use to replace the existing rivets?

Dang it! I knew you were gonna ask that...
Unfortunately I can't tell for sure. I just looked around for some screws and I found the perfect set with nuts to match.

[Rigaud]

I did not disconnect the battery, left it live. Swapped chips and removed the epoxy to dial the idle but only while it wasn't running. The P0505 is due to high idle and the oscillation the ECU searching and needs to learn. I had the oscillation too at first, it went away after a day or two. I had the P0505 popping up every day for two weeks but it took longer every time for it to show up. Eventually all has settled itself and works great. Best direct upgrade I did so far. My installation went fairly well because I did some reading on hear first before doing the job and not after the fact. ;)

Give it some time for your ECU to relearn with the bigger TB.

[tk-421]

My TB came with a big gunk of epoxy on the idle screw, so I just left it as is. I suspect this is what causes a high idle on the first ~30 secs of starting up, but I'm pretty sure that has nothing to do with your CEL.
Then again, tweaking that screw might just do the trick...

[white_rice]

Originally Posted by tk-421

My TB came with a big gunk of epoxy on the idle screw, so I just left it as is. I suspect this is what causes a high idle on the first ~30 secs of starting up, but I'm pretty sure that has nothing to do with your CEL.
Then again, tweaking that screw might just do the trick...

Yeah thats what I'm confused of. Nobody ever seem to have come up with a definite answer as to which one (if either) of these problems was the definite issue causing the CEL. Seems to be more of a hit or miss fix to the problem. Some people appear to have never got the CEL at all. Too many variables here. Suppose I will start with the chip swap and move along from there.