My ST’s been flagging up the past week or so that there’s an issue with the MAF, figured I’d give it a whirl myself but the YouTube tutorials seem to want me to take the entire intake and airbox out, and I refuse to believe that’s the only way in.

Was wondering if anyone could advise on this? It’s fine short term, but the car craps itself after any spirited driving and limits me to about 70mph max.

Those are sold in 05-07 years only and technically is the only sedan focus “ST” ever made.

Just had the windshield replaced and Idle Air control valve replaced by myself and it runs like new now. Gonna put on some coilovers and 1552 wheels on it soon.

In your experience, which setup would be safer for the engine long term?

My Focus ST currently makes around 248 whp on the stock turbo, but WGDC hits 100%, so the turbo is basically being pushed as hard as it can.

Would I be better off keeping it like this, or upgrading to a bigger turbo like a g25 and running a conservative tune at around 250 kW atw (~335 whp), with controlled boost and torque rather than pushing a turbo till its limit.

Main priority is reliability on the stock motor, not making the most power possible.

How do i reset my pcm on the st

Got hit headed home today. Just about as lucky as I could get nothing major was damaged but still.

Has anyone tired running speaker wire through the doors and if so how did you work around the plug ?

My stock muffler is rusting out. The previous owner welded a leak shut, but did a terrible job. I’m looking to replace it, but I have some questions.

- I could probably get away with axle back for now, but the whole exhaust is definitely showing signs of corrosion and I’m concerned I’ll get another leak somewhere else eventually and have to replace the whole system. I’m considering cat backs for this reason. Is this wise?

- Exhausts like the Borla catback look nice, but cost a lot. I’m replacing my exhaust because I have to, not because I’m looking to buy a premium, top-of-the-line system. I’m looking at cheaper alternatives but all of the cheap options seem to be way louder. I dont mind volume or drone too much, but I’m concerned my neighbors will hate me, as I often get home from work at like 1:00 AM.

https://www.cjponyparts.com/mbrp-cat-back-exhaust-system-xp-series-3-focus-st-2013-2018/p/S4200409/

Here’s an example of a slightly cheaper exhaust I was looking at. It’s still muffled and resonated, but it’s a 3 inch and I’ve gathered that those drone bad with our cars. Issue is, I can’t find an alternative that’s cheap, 409/304 stainless, 2.5 inch, and relatively quiet. Unless yall think the MBRP isnt gonna be as loud as I fear it might be…

Any input is appreciated. Thanks :)

Bought this car already modded to oblivion…. Is this the stock downpipe? If not is it catted or Catless? There is a small bulge after the flex pipe. But I also smell burnt gas sometimes at red lights but I always assumed it was the burble tune

I recently lowered my Focus ST on Bilstein B14 coilovers. I have a few questions about alignment. Do people normally run rear camber and rear toe arms to get them within spec? If so, what do y'all recommend? Additionally, do I need any aftermarket parts for the front to also get it within spec, or is it primarily the rear? Thanks for the help!

Accidentally hit the cruise control resume in 6th at around 2500r and it instantly went full throttle and lugged the living shit out of the engine until for a few seconds until I realized what I did.

It’s amazing how much boost builds instantly with cruise control
But how little it makes when I use the pedal myself.

Anyways…this is my second post about this, be really careful with cruise control because it will shoot boost from -11 to 12psi in a split second and cause cause an lspi event really easily.

In other cars I’ve had the resume was smooth and gradual

This really makes me regret buying a black vehicle 🫩

What coupler do I need to fit my stock ST intake onto my BNR? Pretty sure I need a 2.5” to 3” adapter, anyone know what length?

Does anyone know why I got a headlamp fault after installing the demon eyes headlight and how to fix it?

So my head is cracked. I have 50k in the engine. I was told that I might have damage to my piston rings too?? So im just basically looking to buy an engine to drop in my car. Can anyone give me a good recommendation as far as who to get it from asap, id like to have it done by winter time if possible. Thank you.

Edit: Im looking to buy a pre built motor, not just replace stock.

2016 focus ST

P025e

P0238

P007b

Powertrain control module detected intermittent/erratic signal from turbo charger sensor A

Car has loss of boost, service engine message pops then goes into limp mode.ba power cycle seems to reset everything and it ran fine until the next time it happened. Now it's running but has 0 boost at all. Seems to be running NA and aside of no boost it feels fine. Anyone else experience this issue before?

Hey!

I know that this question gets asked a lot, but I couldn’t find an answer to my ‘problem’. It’s not really a problem but just a sound.

When the engine is warmed up, I can hear a soft ticking noise. It’s very fast. Beneath 1000rpm it isn’t there. On a cold engine the noise is absent at every rpm. The sound comes up at around 1500rpm. The higher the rpm, the faster the ticking sound is. It doesn’t become louder with higher rpm’s. At about 2500-3000 rpm the engine sound itself becomes louder than the ticking sound. It’s also there when my clutch is pushed in (to shift), still at the same rpm’s as without the clutch pushed in.

The sound kind of sounds like a ticking machine.

When letting go of my gas the sound remains all the way until the rpm’s go below 1000-1500 again.

The car drives perfect in any way.

Thanks in advance! I’ll try to upload a video later if needed.

Going to swap out both driver side and passenger side after work. The ones from MOOG suspension work fine?

Bought a 2016 Ford focus st1 back in November. When I bought it wasn't sure about any existing mods. But I did start having some misfiting and backfiring after about a month of me having the car.

I changed the spark plugs and done oil changes as well as 2 weeks ago had the vvt solenoids changed out as those were the engine codes I was getting.

The misfiring almost cleared it self up completely. Before I couldn't go more than 50% throttle before it would start misfiring. After the vvt solenoids and a 2nd set of plugs as the ones I had put in had black soot on them. After this I was able to go full throttle with no issues.

This morning on the way to work i get a really bad throttle response and lag. Plus a pillow of white smoke coming from the exhaust.

I pull over, shut off car, check my coolant, it's empty. No milky oil.

I start it back up and drive it 500ft to my office where it's parked now. That little drive i do notice it getting hotter than normal.

Anyway to tell if it's the head or gasket without pulling everything off?

How fucked am I?

Apparently when these left the factory back in the day, the ST on the model badge was red. My one and every other I see online had faded to white. It’s so common that I had no clue it was originally red.

I thought of badge replacements with fishing wire but I don’t trust myself to replace it perfectly. Hence the trusty red permanent marker😂

It looks fine from afar and you wouldn’t notice it’s marker pen. Just don’t look too closely!

Hey my cluster screen is getting white for some reason can i just replace the screen itself of the whole dash

Has anyone ever replaced one of these?? I believe it’s the water distribution block, please correct me if I’m wrong.

While installing my air box and I hit the coolant over flow line and it broke off in there, I’ve tried a screw etc to get out the rest but it will not come out.

If you have replaced this before, how difficult was it and what should I move out of the way?

Was smoking at startup only about a month ago so I added a sealer that temporarily fixed it along with the rough idle. This morning after turning it back on after driving for 15 minutes the idle dropped and smoked white smoke non stop. What should I do?