Engine Woes

I am the owner of a 2000 Maxima. When the car hit 70,000 miles the service engine light turned on. Shortly after the car would violently vibrate when breaking. When I took in the car for servicing (Firestone Auto in Brighton). After running a full diagnostic I was told one of my cylinders was not igniting properly. I followed their recommendations to replace the coils and spark plugs, did an engine tune up, and replaced the rear breaks. I did not follow their recommendation to replace 3 tires.

I left the shop and a day later when I reached 60mph on the highway the service engine light returned. The breaking problem still existed but now the car would stall as well. I took the car back to the shop and was told that they stood by the initial work but missed the second part of the problem. After thinking it was maybe a vacuum leak they determined it was the motor oxygen sensor that was still preventing the cylinder from igniting properly. The manager was great with customer service, kept me in the loop of what was going on, did not charge me for labor and gave me an assurance that if this did not solve the problem he would reimburse me in full.

When I was called to get the car I was asked if I noticed any exhaust issues and that they recommend I do a full muffler/exhaust replacement for another $734–None of this issues were detected on the original diagnostic just 2 weeks before, nor was there any smoke or smell being omitted from the muffler prior to bringing in the car. I went to pick it up last night and as I turned on the ignition there was a vibration present throughout the car, it continued as i reversed went around the lot and then entered back into the parking space. I went back into the shop and reported the problem. They took a look, asked me to leave the car, and I have yet to hear back.

Any recommendation/suggestions as to what may be causing the problem?

Get a second independent opinion. I would also suggest you take your car to get any error codes read and post them back here. Some auto part stores will read them for free. Try Autozone or Advanced Auto Parts.

There is nothing that they told you or did that might not be right or true. It is just not possible from here to tell. The error codes will help however.

Why did they say you needed to replace the three tyres. I might suggest that normally they would recommend one or two or four. Three seems rather odd. I would also suggest that if they were correct about the recommendation to replace the tyres, it could be a safety issue and not something you should ignore.

Did they replace the rotors along with the brakes? Did the vibration stop?