Protege 5 engine running rough despite repairs

[trade350]

CEL code P0705 Transmission Switch

ok here is the summary

Car went dead, would not crank enough to start.
Replaced battery.
Everything is fine, until I returned from a trip. CEL is on plus OD light blinking


Now think about this.. could something really have gone wrong immediately after I put in a new battery?

Ok went to Autozone did the OBD, start up the car w/OBD connected and NO CEL !!!! But the OBD still read code P0705 Transmission Switch.

***Somewhere on these forums I read that if you get a CEL to drive the car 3 more times and it will go away. Well when I restarted the car, that was the 4th time.
Anyone think I am going to run around and replace the trans switch? Car works fine. I am not going to replace the MAF for $400, or the EGR valve or the coils, wires, or plugs. Nor am I going to replace the Catalytic Converter- even if the OBD code says to. I will do it OLD SCHOOL, when the part itself breaks, then I will replace it. That's how we did it on Chevys. F'in computers! I read all these people jumping around replacing parts because OBD said to. Anyone consider replacing or checking what causes the CEL to come on???? Couldn't the CEL be the problem? it is after all a computer. I get computer errors on my desktop daily. i don't run out and replace parts or buy software that says it will stop the errors even.
I tell you, if you have a sluggish car and CEL and you take the negative terminal off the battery for 15 minutes, put it back on and the car runs fine, that tells me there is NOTHING wrong but the CEL [check engine light]. Fix that instead. Go to the dealer, say there is nothing wrong with my car but I have a broken CEL can you fix it so it stops coming on?

 

[shane02pro5]

Maybe a short check the plugs and harness to the tranny... maybe something got kicked up under there and damaged the sensor or a wire?????

 

[dleamon]

Engine Running Rough

Glad I found the forum. I have the same problem as others. A rough running engine with even less power than before (engine light is on). My 2000 Mazda Protege has 197,000 trouble free miles to this point and I would like more. I took it to the dealer and they changed a spark plug wire with a total bill of $170. That just solved part of the problem. I left the dealer and the light went on again. I will look into the ideas shared by others. If there is a definite answer to my problem, please share.

Dan

 

[patsissons]

just had another p0300 tonight, but this time the misfire lasted for about 10 minutes before correcting itself. Usually it only lasts about 30 to 60 seconds. I have also noticed that there is a faint smell of burning rubber under the hood after these incidents, could also be burning oil. that worries me a lot more tho, since i really don't need a belt failing me any time soon. I also don't want to take it back to mazda for the third time, and for the third time have them tell me nothing is wrong, just getting to pricey haha.

 

[shadowncs]

Couldn't the CEL be the problem? it is after all a computer. I get computer errors on my desktop daily. i don't run out and replace parts or buy software that says it will stop the errors even.
I tell you, if you have a sluggish car and CEL and you take the negative terminal off the battery for 15 minutes, put it back on and the car runs fine, that tells me there is NOTHING wrong but the CEL [check engine light].

While computer error is not unheard of, it's highly unlikely. The difference between your desktop and your car computer is that the car computer is waaaay simpler and a LOT better tested - after all it is essential for running the engine.
You have to look deeper, because 99.9% your CEL/OD had a real cause. By real cause I mean either a condition that would cause the sensor to report the out-of-bounds condition or a faulty sensor, which is quite common. Or faulty connection/wiring. Anyway you look at it, if it goes away it will probably come back at some point.
The reason it goes away when you disconnect the battery is that you do a "reset" on the computer and certain tests (that could generate a CEL) need certain driving conditions. Until those conditions are met the computer assumes no problems, not giving you a CEL. For example, if you have a bad 4th gear auto switch, it will only show up when the computer tries to engage the 4th gear, not sooner.

I know, not very helpful but hope it sheds some light. Disclosure - I'm a software engineer.

 

[dleamon]

Mazda Protege Engine Running Rough - Repair Suggestion

Re: Engine running rough

Mazda Protg 2000 - 197,000 miles

I had a similar problem as others. Engine light on. Engine running rough. Lack of power, etc. After a failed diagnosis at the dealer I went on this forum and received the following suggestion that worked.

I bought two new coils along with wires and spark plugs. $350 later - runs like a champ.

I hope this helps someone.

Dan

 

[pasadena_commut]

I took it to the dealer and they changed a spark plug wire with a total bill of $170.

Do yourself a big favor and do that sort of work yourself. You could have replaced both coils, all 4 plugs, and both wires, plus bought a cheap socket set to do it with, for that amount. If you must have somebody else do it, find an independent mechanic.

 

[patsissons]

Interesting... received a P0421 today, wondering if that has anything to do with my P0300's. Any thoughts?

 

[ghettoracingkid]

i think they usually go hand and hand