I have a 2001 Infiniti Q45 with 143,000 miles on it. For some time it has had a problem with occasionally running extremely rough.
This problem usually occurs when we first start the car, but it may also occur after we have been driving it for a while. Some times we can turn the ignition off then restart the engine and the problem is gone, other times it is still there. Any time it is running rough the "TCS off" and the SLIP lights are on. Usually it runs like an angel other times it runs like the devil. Is it demon possessed?
You may start with replacing plug,s,if you haven,t all ready,then replace the coil pack,s,there is one for each plug,take it and have it scanned ,may get lucky and show you which pack,or pack,s need replacing,without having to do all,this has been a known issue with the infiniti,and a lot of people have sufferd, the same as you,hope this help,s.
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