2009 Toyota Matrix, 1.8L, 163K automatic with no major issues. I admit to never changing the ATF fluid but that is on me and from what I have read in the FAQ it's too late, but surprisingly the fluid doesn't look that bad. So, for the past month I have noticed the car stutters/hesitates around 35 mph and by the time it gets to 40 mph it's fine. This also doesn't happen on every acceleration, can't pinpoint it. Oil and filters are changed on time, spark plugs and coils replace a couple years ago, MAF cleaned 3 years ago. I have not scanned for codes but wanted to see what opinions could be on this or if anyone has experienced random 35 mph hesitations. Thank you.
Hopefully it is not a transmission issue. Try checking fuel pressure and cleaning fuel injectors. Clean the MAF again as well as the throttle body. Fuel filter would also be suspect at that age and mileage but it's not easily replaceable, being part of the pump assembly.
Really what should be done is to check for codes, and record live data while the problem happens so it can be played back and analyzed. That's an essential part of diagnosing problems on modern cars.
Thanks! What product would you suggest for 'cleaning fuel injectors'?
Thanks! What product would you suggest for 'cleaning fuel injectors'?
Scotty likes the ATS "Carbon Clean" products but those appear to be out of stock currently, probably supply chain problems:
https://www.atscarbonclean.com/shop/
In the absence of the ATS products I would try one of the leading brands of PEA-based cleaners like Techron.
Thank you so much, one last question... i'm going to do what you say and I may be over thinking this but is there a proper order in doing all of this? For example should I apply the Techron cleaner into tank first, then clean throttle and MAF a week later, or it doesn't matter?
As far as I know it doesn't matter.