bostoneo
The Chosen One
This has been a fun past 12months for car issues for me!
So... in Nov 2017 my 2010 Mazda3's engine began to hesitate when idle, it would rev up to 1250rpm, drop slowly to under 1k rpm and do it again... sometimes the engine would just die out completely and I'd have to restart the car, fun in stop and go highway traffic. So I took it to the shop, they did tests and determined one of the two O2 sensors was running lazy, replaced and was running fine for 2 months until Jan 2018 when it exhibited the same issue again!
So, knowing my K&N air filter was coming up on 50k mi when it needs cleaned etc, I decided to go buy a standard paper air filter to see if anything would happen. It appeared to fix the issue until another month later in feburary, same issue! Took it to the same shop and the owner dug into it for a couple days and determined the other O2 sensor was failing to. I ran to mazda dealer and picked up the OEM replacement, installed, same issue. So they cleaned the throttle body from a bunch of carbon buildup and did a vac test which passed, and probably some other things I don't remember... still an issue. The mechanic noted that when rev'ing over 3k RPM the tach would bounce down about 250rpm back and forth.
So now, the troubleshooting process has led me to put in some fuel injector cleaner and a tank of premium gas to run through to see if the issue improves as it may be restricted fuel injectors... Anyone have some input that might help? I am getting no codes from my OBDII scanner (bluedriver) nor check engine lights. Also noticed since going to shop Saturday and putting in fuel injector cleaner / premium gas in tank, get some white smoke, which looks like exhaust maybe... Thought I was tripping at first lol.
So... in Nov 2017 my 2010 Mazda3's engine began to hesitate when idle, it would rev up to 1250rpm, drop slowly to under 1k rpm and do it again... sometimes the engine would just die out completely and I'd have to restart the car, fun in stop and go highway traffic. So I took it to the shop, they did tests and determined one of the two O2 sensors was running lazy, replaced and was running fine for 2 months until Jan 2018 when it exhibited the same issue again!
So, knowing my K&N air filter was coming up on 50k mi when it needs cleaned etc, I decided to go buy a standard paper air filter to see if anything would happen. It appeared to fix the issue until another month later in feburary, same issue! Took it to the same shop and the owner dug into it for a couple days and determined the other O2 sensor was failing to. I ran to mazda dealer and picked up the OEM replacement, installed, same issue. So they cleaned the throttle body from a bunch of carbon buildup and did a vac test which passed, and probably some other things I don't remember... still an issue. The mechanic noted that when rev'ing over 3k RPM the tach would bounce down about 250rpm back and forth.
So now, the troubleshooting process has led me to put in some fuel injector cleaner and a tank of premium gas to run through to see if the issue improves as it may be restricted fuel injectors... Anyone have some input that might help? I am getting no codes from my OBDII scanner (bluedriver) nor check engine lights. Also noticed since going to shop Saturday and putting in fuel injector cleaner / premium gas in tank, get some white smoke, which looks like exhaust maybe... Thought I was tripping at first lol.