Hi I have a 2004 Mazda, Manual with 40k miles.

Recently been having a few problems. Removed the cat as it broke and am now having an issue because the cat sensor is not giving the correct info to engine and is running a little rough. Any ideas I dont want to put the cat back on because the last one blew on me and they want 1000 Euros to replace the new one in spain and there is no warrenty on cat over here.

Also recently the car has been a little shakey at high speeds and whilst breaking or accelaerating hard. Tyres and breaks all fine, any one know how I can tell if the engine mounts are ok, and if I do have to change them how hard is this to do?

Thanks,
Jerry

 

Taking the cat off is fine.

If the car is shaky at high speeds its probably because you need an alignment.

Easiest way to check the engine mounts is to take off the wheels and look at them. They will be torn if they are bad. If you take off the wheel you will see a aluminum bracket connected to a rubber mount with three blue dots on it. That is the engine mount.

Likely a 4 wheel alignment will solve your problem.

 

it could also be back pressure due to a carbon build up. there exists a very sophisticated method for this

1. warm up the car.
2. take it to the rev limit with the air conditioner on and running at full blast
3. decelerate to 30 ish mph
4. repeate step 2 for 2 min.
5. pull over to the side of the road.

if in 2 min the check engine light comes on ... you need another cat. if not .... congrads ... all the carbon is out

If the check engine comes on ... take out both o2 sensors and spray them with some brake degreaser and put them back in.

the guy who did your cat may have ommited that very important step.


there is also a tsp for loss of power in which they decarb your vacuum lines... if you still have it under warentee get that done as well.




besides all that ... if its a localized vibration .... you may just need to ballance a tire. im not there so this is all guess work. if you just had a clogged cat ... the above will work.