IMO now this is confusing. You should make a new thread as this was the OPs. He's the one who I was addressing.

 

We were trying to trouble shoot, what appears to be, the same issue. I thought it made sense to try to harmonize trouble shooting issues. I will stop responding.

 

I still think you need to check the MAF one more time. As I wrote preferably swapping it out with one from another car that you know is running properly.

 

Update from my end; I am having the new TB and plenum installed Wednesday, I will probably have a pretty good idea after my next cold start if I have solved the problem.

Yesterday, when I started the car, I did the same 2k hold until the choke went off - no problems.

Once the car was up to temperature, I noticed that there is a little hesitation/stumble upon throttle tip in, but it didn't send a code.

So, we shall see...

 

Keep us posted, a new throttle body, albeit not cheap, is an easy solution.

 

Will do,

Cheers,

 

Did the new TB fix your issue?

 

I did not have time to pick it up Friday, long weekend here, so I will not know until Tuesday.

 

*UPDATE*

Picked her up, and had the opportunity to do a cold start.

Made it through cold start/choking procedure without a misfire or too rich code! (Yay!)

And, as an added bonus (after I reset the throttle again), my off idle hesitation/stumble is gone, AND, throttle is now super snappy and doesn't almost stall when I blip it. I would say, after looking at how the old TB is gummed up, this most certainly has addressed issues that although were not debilitating, sure irritated me to no end.

As far as power delivery is concerned, I only got to drive it a couple of miles, but it is most certainly much smoother than it was - with that, I cannot comment on if there have been any major power gains, until I get it on a dyno...

Thanks everyone for the comments!!!

 

YES!

 

Congratulations. Hopefully its a permanent fix!

 

It goes to supporting the fact that the Bosch engine control unit is a more advanced system for 2003 than I was expecting; it most certainly likes to operate within a set of parameters and not deviate whatsoever...

 

So I cleaned my throttle body 2 weeks ago. It also was dirty and what looked like dirty enough to cause the issues. It didn't do anything for my problems. I similar to you had the misfires, but also the almost stalling when blipping the throttle (particularly blipping it to 2000 rpm, other ranges it comes back better). I ordered 48k used throttle body too, and it did the same thing.

Although our problems appear to be 100% the same, our solutions are probably different.

 

I was leaning towards the TB because of how the engine was behaving, and because I was aware it was drive by wire. I had a similar (actually, totally different) bunging problem with my STi when we were tuning it a glob of oil, suspected to be from the turbo, ended up in the intake. It then, of course gummed up the TB. As the Sti was my first experience with drive by wire, and the car was no longer running, I took it all apart, dumped it in the parts washer for a day, and all was good after applying some fine machine oil.

After changing coils, plugs, etc etc, and the hesitation was still there, it reminded me of the issue with the STi, and I am happy it did.

I'm leaving the office now - going to see how much better it really is!