Anyone have ideas on what could be causing this problem? 2017 Ford Fiesta S acting up

I had the purge valve changed a few months back. Now, when I’m driving, the car acts like it’s not getting any gas for about 30 minutes before returning to normal. Tried letting it sit—sometimes it revs a bit, but then it loses power again. It also stalled out on me once when I got in.

This has been going on for two months and keeps getting worse. The check engine light would turn off when I restarted the car, but now it stays on most of the time.

When it acts up, it shakes, the RPM drops, and pressing the gas does nothing—it just rolls along in drive.

Sounds like it could be the throttle body. Try cleaning it and resetting the idle. If it’s still giving you trouble after that, might be time to replace the throttle body and do another idle reset.

Mia said:
Sounds like it could be the throttle body. Try cleaning it and resetting the idle. If it’s still giving you trouble after that, might be time to replace the throttle body and do another idle reset.

Yep, I’m a tech too. I bought a new Bosch throttle body for around 50 bucks on RockAuto. It’s a common issue. You can also reset it by disconnecting the battery and doing the relearn process. You can find guides on YouTube.

Having a similar issue, started with a wrench light coming on now and then, and now it’s on almost all the time with symptoms getting worse. Are you getting any readable codes?

scott1 said:
Having a similar issue, started with a wrench light coming on now and then, and now it’s on almost all the time with symptoms getting worse. Are you getting any readable codes?

Haven’t had a chance to go to a shop yet because I kept putting it off, but I’m planning to take it tomorrow for a code check if I can even make it there :sob:. The check engine light is on, but if there aren’t any codes, I might try a mechanic with a better reader. I’ll update with whatever comes up.

I think it could be the fuel filter (hoping it’s that since it’s cheaper) or maybe the fuel pump failing. This all started after I did a gas treatment.

@Gale
Had something similar happen when my transmission went out. If you’re in the US, AutoZone and O’Reilly will read any error codes for free.

scott1 said:
Having a similar issue, started with a wrench light coming on now and then, and now it’s on almost all the time with symptoms getting worse. Are you getting any readable codes?

Just checked it, and the code reader says: ‘Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation.’

I’d take it back to the shop that worked on your purge valve and have them double-check their work.

Does it stall completely? Could be the throttle body acting up.

Could be oil or some debris in the inlet. Try cleaning your air filter and the inlet pipes, then give the inlet a good clean with brake cleaner.

I had a similar issue with my partner’s 207 when the oil cap popped off and sprayed oil all over the engine bay.

This definitely sounds like an engine problem. I’d suggest getting it checked sooner rather than later.

Ann said:
This definitely sounds like an engine problem. I’d suggest getting it checked sooner rather than later.

Wow, that’s super helpful advice :roll_eyes:.

Gilbert said:

Ann said:
This definitely sounds like an engine problem. I’d suggest getting it checked sooner rather than later.

Wow, that’s super helpful advice :roll_eyes:.

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Sounds like an issue with the mass air flow (MAF) sensor, which should be located on the air filter box. Cleaning it might not be enough in this case, so you might need a new one.

Weston said:
Sounds like an issue with the mass air flow (MAF) sensor, which should be located on the air filter box. Cleaning it might not be enough in this case, so you might need a new one.

You could try swapping it with the MAF sensor from a similar car just to test it out—it’s an easy switch. There are some good tutorial videos on YouTube.

Is that a small flashing indicator light? Just wondering what it could be.

Mechanic here—be cautious with the 2017 model. This could be a timing issue, maybe a tooth off, which would explain the stalling and the check engine light.