Last thursday there was a terrible smell in my car and i have had a cat go bad before and that is exactly what it smelled like... i pulled into midas a local shop because i know some fellas there and they took a wiff.. it was not coming from the engine bay nor was it coming from the exhaust so they guessed spark plugs and they were right. i replaced my spark plugs that had to be bought from mazda directly because it was to late at night for anywhere else to be open and i was going on a trip the next day ($190)... but i dont want to talk about that expense haha.... i was hoping that this would fix my rough idle issues because my car shakes so bad that it shakes my leg and the tach jumps from 500 to about 1200 back and fourth about every 10 seconds i am stopped..... i went and got a OBD and checked my codes im throwing a code for the rear 02 sensor which makes sense since i dont have one lol... so now my question is what is my next step to look into this problem.

only mod that is done to the car is an intake which SHOULD make it run smoother i assume? but other than that no engine mods have been done

thanks members

 

How many miles on your coils?

 

hard to tell... i bought the car used and when i put the new motor in i used my old coils.. i guess i should go that route.. if i do ill just go with the bhr ignition system

 

- leak somewhere at intake or vacuum
- leaking fuel lines or low fuel pressure
- clogged or broken injectors

you didn't mention when exactely the idle problem came up? after engine change? after plug change?

 

mine was doing the same thing a few weeks ago and would get a misfire when trying to go wot....coils and plugs fixed the problem....

 

BHR here i come

 

check the plug wires