exceleration hesitation

[BobOki]

I have been experiancing hesitation when going from full stop. I have also been experiancing stutters while sitting at lights.
If I throw it in park, it will not stutter, but in drive it will go down below 500 rpms almost stalling, then jump up over 1000rpms and then back to the 750 or whatever it idles at.
I have about 120k miles. I recently added a CAI, ngk iridium plugs, and magnacor wires. (plugs and wires were just last week). I just had my tranny flushed and the filter replaced.
I HAD changed my front o2 sensor a couple months back (no more than 12-20k miles ago) and I was getting a 402 (I think 402 or 420) which I was told was o2 sensor. I had the error cleared yesterday and it has not yet come back on. I was also told that just unplugging the battery does not reset the ecu, and that it actually stores all the data on it in persistent memory. That surprised me.

Any ideas what else can be causing my problem?

Lastly, I am thinking about putting on a new exhaust system and new headers, anyone know some good (performance) brands and where to purchase for our cars, or if it is even worth it.? Finding stuff for a 1.8L is like pulling teeth! I am also considering an UD pulley.

 

[DiS]

maybe your EGR valve is clogged up from carbon build up? Try cleaning it, and see what happens.

 

[BobOki]

maybe your EGR valve is clogged up from carbon build up? Try cleaning it, and see what happens.

I tried locating it on my 1.8L, but unlike the 1.6 and the 2.0, its not very obvious where it is.
Does anyone have pictures or a detailed description?

Btw, I just seafoamed my engine, bout to go get the oil changed..... I would LOVE to do the egr!

 

[cplagge]

I have some hesitation too, in my manual though... just feels like it doesnt wanna go, then above 1200 RPMs its good... dunno why.

 

[BobOki]

Well I have helped it out SOME.....
What you do is take off the brake booster line and slowly let it suck some seafoam into the lines. 1/3 the bottle is all you use. After thats done, let it sit in your car for about 10-15 minutes, then start your car up and let all the crazy white smoke go away. After thats done you need to reset the ecm, which is just unplug your battery and hold the - and the + together for a minute or two.
Once all thats done CHANGE YOUR OIL! The carbon it cleans will BE IN YOUR OIL, so you MUST change the oil! 100% MUST!
After thats done, dump the rest of the bottle of seafoam in your gas tank and enjoy.
The brake line booster can be found in the upper right hand side of the engine. There is a large black circle disc with a hose plugging into it, the hose is clamped. Thats the brake booster line hose. Unclip it and let it suck in the seafoam. It WILL try to kill your engine, so you need to prop the engine at throttle up to about 3000rpm or so, or get another person to help you out.

I still need to know WHERE the egr is on our 99 protege 1.8Ls! Anyone that can help me out with a picture or detailed description will be my hero! (the how-to on cleaning the egr is great, but thats a 2.0l protege and my egr is NOT where they show.)

 

[BobOki]

Score!

 

[ANTIXPRO]

I had that problem too a few weeks ago. Hesitation from a complete stop to go, but my problem was from steam cleaning my engine bay and getting my moisture in and around my plug wires. I just used an air gun to blow them dry and it was fixed. Try looking into that.