Check Engine Light
 

I picked up my car around 2 weeks ago. While driving home the Check engine light came on. I took it to the dealer the next day and they said that the oxygen sensor was loose. They tighten it. While driving home again, the check engine light came on again. I brought it back to the dealer. They reset the code and mentioned that probably cheap has was put in when they handed me the vehicle. They told me to drive the car with a new tank of gas. While driving home again, the check engine light came back on. I took the car back to the dealer. This time to took the car for a week and replaced the Oxygen sensors. I just picked up the car today and while driving home again the check engine light came back on. It looks like the light comes on after 40 miles of driving after the codes has been clear. Any suggestions.

Sounds like your dealers aren't fixing the issue... they are probably treating symptoms rather than the cause.

Probably not much you can do except keep taking it back to them and if they cant fix it, ask them to give you a new car since they seem to be unable to fix the problem.

Without knowing what the error codes are that is causing the light to come on, it's pretty difficult to diagnose from here.

Maybe something wrong with the ecu itself?

There is a PCM reflash for incorrectly set MIL, make sure they have done that first.
I wouldn't bother going back to the same dealer, unless they promise to call MNAO for support before you take the car in. The cause could be anything, it needs to be diagnosed by an informed technician...

Your dealer sounds like they are just trying to do a cheap quick fix. I would just keep going back and back until they do it right. I would also mention to them that you did not pay 30k for a car you only get to drive for 40miles at a time!

I spoke with a customer service manager and he mentioned that he has no problem giving me a new car as long as the service manager gets the go ahead directly from Mazda. I have oppened a case with Mazda and they mentioned that it would be a legal matter dealing with my state lemon law.

dude what are the codes they find when they check the CEL? if you dont have them get them.

Today I took the car to a different dealer. The rep mentioned that they were going to flash the ECU with a new software. The technician had told the rep that he has seen the problem before. The rep mentioned that most likely is a problem with the Catalyst. Let's see how it goes. They are actually going work on the car tomorrow. I'll let you guys know how it goes after I get the car back and drive 40 miles or so.

I got a printout and it said P0420.

Yeah, that's a Cat/PCM/Oxy sensor fault code....take it back and get them to try again.....

Gomez.

yep the flash will take care of it IF it is a false code. it won't help if there is actually something wrong with your cat now.

I took the car to a different dealer yesterday morning. The customer service rep mentioned called me and informed me that the tech knows what the problem is, but he was not able to work on the car yesterday. They would work on it today or tomorrow. I also called Mazda Corporate and they put me on a rental car in the mean time.

I got the car back on Monday from the Second dealer. They reposition the EVAP Hose which was disconnected. This was the cause of the Check Engine. They Re-Flash the ECU and performed all recalls on the vehicle. That night I put 120 miles on the car and the check engine light did NOT come on. I'm still testing the car. Looks good so far.