I just want to start by saying I'm new here so bare with me. I've also searched the forum before I even became member and can't find the problem.
The car will idle perfect after it's warmed up, but when it's in any gear the motor just has a jerk to it, but when in park and neutral it idles smooth.
Replaced all Vac lines,TB gasket, Cleaned Maf, cleaned IAC valve, and cleaned EGR ports in intake. I cannot find any leaks anywhere, I've also replaced Plugs,wires,rotor and button. Can someone PLEASE point me in the right direction? ALso I have no CEL on and I've scanned it multiple times and nothing reads...Many thanks to you all

 

any ideas at all?

 

Hmm, only missing when in gear points to a cracked air filter to throttle body boot. The engine moves when in gear and opens the crack further. If not that then i can't think of any other component that would care whether it is in gear or not. Are you using a flammable brake cleaner spray to check for vacuum leaks?

 

I thought it would be the air intake as well but I put a new one on and it still does the same thing. I've used starting fluid and TB cleaner to check for Vac leaks but not a flammable brake cleaner

 

Let's change strategy for a bit. You say in your first post that it idles fine once warmed up. Elaborate on how it runs/starts cold.

 

It always has the slight miss when in gear. It runs smooth when the motor is cold and you can't really tell there is a miss when it's warming up even when in gear. When driving it has a slight miss every now and then, but it will always have a small miss when it's in any gear sitting still, but when you put it in P or N it seems like the miss goes away.It will also idle high when you put it in P or N for a few seconds, sometimes maybe a little longer. I've tried basically everything I can think of

 

Add a bottle of TECHRON to the gas tank.

 

I've ran a few different cleaners through it and none has helped so far. may give it a shot, hell it can't hurt

 

ok so I have a update on this problem. It started hesitating really bad this morning while driving before the engine was fully warmed up. It also had a high idle while in P and N but when you put it in gear the rpm's drop to normal range and then it would start the choppy idle while idling in gear. While driving the car when the miss occurs, it's like you turn the key off and then right back on. The rpm's drop 1500 or so and then they return back to the location they were at when the miss happened. The miss is for just a split second. another thing, I rarely drive the car, so it's not like I experience this everyday to see if it will throw a CEL

 

i dont have any personal experience with the 2.5. i suggest you go to the other site, mazdaworld.org. you will have to register. then go to the millenia section, and look for posts from kutch, and yel-low. both have extensive knowledge of the 2.5. i have seen several posts on main relay problems with symptoms similar to yours. i have never seen or experienced main relay problems on the 2.3. also, i have seen a lot of posts on the ignition distributor problems. again, the 2.3 does not have one.