My wife drives the Mazda 5 and has said for the last couple weeks, on occasion when she hits the gas leaving the work parking garage, there will be a delay, then a sudden surge. She says it has happened before while going uphill down the interstate.

My forst fear is transmission slipping, but since it shifts in and out with no hesitation 99% of the time, I'm guessing it isn't the problem.

She drives alot and has 110,000 on a 2007 mazda 5 sport. Should i head directly to the shop and pay them to diagnose the issue or would it be safe to have her just pay jiffy lube to change the fuel filter and add injector cleaner? The cost is about the same but i don't want to pay the diagnosis fee just to have them then say I just need to replace the fuel filter.

I don't believe the fuel filter has ever been changed. Are these symptoms of a partially clogged filter?

Thanks

 

As it's intermittent it may be difficult to diagnose. I'd get the fuel filter changed anyway as it should have been done by now and see if that makes a difference. I don't think it will, but it could.
The fault sounds more likely to be a sensor fault. It could be a dirty MAP sensor or Air Flow Meter. Check also for split vacuum/air inlet hoses.

 

Thanks for the answer. I called the dealership and they agreed that because it was intermittent it would be really hard to diagnose. Jiffy lube says they can't change the fuel filter because it's not accessible so I'm just going to have the do a fuel system cleaning and see if that works.. They claim it will clean the filter and injectors. We'll see.