i bought a used 03 6 for my daughter. one morning i wouldn't start. when i gave itboost it went into what i was told was a limp home mode. i tested the battery and it checked good.i was told it may not be the right one so i ordered the right one from the parts store but sometimes it still goes into he limp home mode what cause it to go into limp home??

 

the battery will have little effect on the way the engine runs. Is the CEL on? what is the vehicle doing that tells you its in "limp home" mode.

possible something was shorted out while boosting?

 

Yep, check & see if the CEL is illuminated. If it is, take it & have whatever codes pulled & post them here. We can then help you better from there.

-Sheldon.

 

took it to a mech and i got a bad coil or wire or plug on #4 and a bad computer any one know the price of a computer ?? will a salvage one be ok or just get a new one??

 

A salvage yard might be the cheapest way to go. Make sure the part number matches, there are different engine types for the mazda 6.

 

so when i look for the part i need to look for a cel??i bought a alldata disc but didn't help me much kinda hard to find my way around it i wanted a service manual don't guess they have books anymore

 

i need to look for a ECU???

 

You cannot just change the PCM in our cars. We have what they call a CAN system. Get the codes & post them.

 

I recently replaced the oil in my rx8 , unfortunalty I putt in 10w40 synthetic oil. I don't know if this has effected the engine, but since then the car has been feeling very sluggish. It won't go over 6000 revs as easily any more. I don't know much about this.limp mode, but think I may have it. The car feels very slow. I have since drained the oil from the car, and replaced it with semi- synthetic 5w30 and replaced the oil filter, still no joy, the car still feels very sluggish and makes a weird noise unto and after 6000 revs, can some one please help, what is the problem?

 

Per the Owner's Manual that came with your car, "Do not use either synthetic or semisynthetic motor oil."

Were I in your shoes I'd get that stuff out of there and go back to the required 5W-20 oil.