The P0420 code indicates a problem with catalytic convertor function. This can be the result of a failed catalytic convertor but more commonly from a failed O2 sensor. It is diagnosed by testing the O2 sensors and replacing if bad, and then repolacing the catalytic convertor if there's still a code.
Bought a modded Fiesta ST but...
- Thread starter 61CAV
- Start date
Thread Starter
#43
https://www.summitracing.com/search/brand/edge-products
How about this? Just an idea
How about this? Just an idea
A Cobb AP is not exactly cheap, so unless you just have no care about where your money goes and you enjoy going on potential wild goose hunts, Iād suggest just pausing on any purchases until you know exactly what youāre dealing with, and knowing what the best course of action is to deal with whatever youāre dealing with.
Friendly advice: slow down, listen to everyoneās input here, and just wait til you know what your car has. Everyoneās been super patient here trying to help, but this could quickly turn into a train wreck if you decide to get a bunch of parts without knowing whatās what.
Im looking to replace old parts that wear down. If an upgraded clutch is better than a stock one, I'd choose a better one, If I get to the point.
The P0420 code could be either failed o2 sensor or the previous owner installed an aftermarket downpipe with high flow cat or catless. Do you have a way to get under the car?
Take some more pics of the engine bay and weāll help identify stuff. Get the front down by the throttle body (between the engine and the front of the car), up under the cowl at the back of the engine, and from underneath if you can.
Can see in the first pic an Injen CAI and whoosh induction hose. Your crossover pipe looks aftermarket too but canāt tell with certainty from the photos. Here are links to the shit you have already.
https://whooshmotorsports.com/colle...ta-st-1-6l-turbo-4cyl-wrinkle-black-short-ram
https://whooshmotorsports.com/produ...low-silicone-induction-hose-kit-free-shipping
Take some more pics of the engine bay and weāll help identify stuff. Get the front down by the throttle body (between the engine and the front of the car), up under the cowl at the back of the engine, and from underneath if you can.
Can see in the first pic an Injen CAI and whoosh induction hose. Your crossover pipe looks aftermarket too but canāt tell with certainty from the photos. Here are links to the shit you have already.
https://whooshmotorsports.com/colle...ta-st-1-6l-turbo-4cyl-wrinkle-black-short-ram
https://whooshmotorsports.com/produ...low-silicone-induction-hose-kit-free-shipping
Thread Starter
#49
Thank you. So under further review, I got a new oil change. Im not sure what was used, but my next oil change is in 150,000 miles. But regardless im going to get it changed way sooner. Fuel injectors were cleaned, and its all straight pipe. :/ I learned the average oil change shop does Trans fluid change, but not on Fords Fiesta STs. :/ so only ford dealerships, or a certified mechanic.
Your receipt or even the sticker on the windshield should say what oil was used. It should be at minimum semisynthetic like the OEM Motorcraft oil. The weight is 5W-20. The manual suggests a pretty long oil change interval and there is a wrench-shaped light on the dash that will tell you when to change the oil (also on a long interval). But probably almost everyone on this forum changes the oil at 5,000 miles or maybe even 3,000 miles.
Transmission oil needs to be a very specific type so it is a good idea to stick with a Ford dealer for that.
If the car is straight piped that explains your P0420. Personally I would not leave it that way. The catalyst does not hurt performance, and everything is better about having it working. The ECU changes things depending on what the O2 sensors read, and if there's no catalyst it will be getting bad readings all the time. And pollution is a bad idea.
The car sounds like crap without a full exhaust system with resonators and mufflers.
Transmission oil needs to be a very specific type so it is a good idea to stick with a Ford dealer for that.
If the car is straight piped that explains your P0420. Personally I would not leave it that way. The catalyst does not hurt performance, and everything is better about having it working. The ECU changes things depending on what the O2 sensors read, and if there's no catalyst it will be getting bad readings all the time. And pollution is a bad idea.
The car sounds like crap without a full exhaust system with resonators and mufflers.
Thread Starter
#51
I would be in that range of 3-5k anyways. I had straight pipe on my 350z, and it wasn't bad. But I need something better on the ST forsure. Now, we've established a straight pipe, what is a good exhaust system? Please dont say stock, but if I have to, I will. It will remove my 0420 code atleast. I dont need a cop follow me around again.
There are plenty of threads about exhausts on the forum to peruse and read about the various exhausts available. None of them provide better performance than the stock exhaust though. It was well designed to begin with. The aftermarket exhausts primarily offer more noise/drone to varying degrees, along with maybe a prettier tailpipe.
Just catching up here, some of this may be redundant. I genuinely am trying to be helpful but have a bit of a gruff writing voice.
1. Edge doesn't tune these cars, they sell something that adjusts the throttle response. This should not be installed on your car and should be recycled as e-Waste.
2. Your primary goal here should be preventative maintenance and familiarizing yourself with the vehicle itself. Fluid changes, wear-and-tear items, etc. This includes figuring out what modifications have been done to the car already (see point 3 below, though as noted we can also help with photos).
3. If you want to tune the car, this is a whole different can of worms. Your best bet on this front is to find a shop that you like and trust and is familiar enough with the Fiesta ST platform that they can tell you what's already been done to the car. Oakos in Sterling Heights or MAPerformance in Wrightstown WI are both reputable shops in your general neck of the woods, though in looking at their website I think MAPerformance may have been bought out by someone else.
Once you find out what has been done to the car, you'll want to find a tuner - there are many good ones, the three most commonly recommended on here as far as I know are Dizzy, Stratified, and Tune+. All of these guys are perfectly competent to tune your car and just depends on who you vibe with. You will want to contact them with your goals for the car - "daily driver but a little zippier?" "track car?" etc - and ask them what parts you should buy and install to achieve these goals. This will save you time, guesswork, and money. These people are professionals. If they say "buy this intake and this set of spark plugs and do not buy this intercooler," your job is to buy those things. If they say "jump," you say "how high?" From here it is a process of having the parts installed on the car and getting a tune installed via a Cobb AccessPort. All of this is going to be expensive. The "how much does that cost?" number is going to have a comma in it.
4. You do not pick up any power on this car with an exhaust unless you have a big turbo. If you are running a straight pipe with a catless downpipe (causing the p0420) and no tune, it is possible that you bought a time bomb and getting either a tune or a replacement catted exhaust should be high on your list of priorities. The stock exhaust is perfectly adequate, it just sounds boring. If you want better sound, get any of the 2.5" options such as the Cobb, Mountune, or Ford Performance, or, if you want the big 3" exhaust, shell out for the Thermal R&D. Most of the others are designed in such a way that they generate so much drone and pressure inside the car that it can actually damage your hearing. The Thermal R&D does not. The CP-E Nexus exhaust is better than most of the other options but not as good as the Thermal. I have also heard good things about the GReddy exhaust, but it's very uncommon and I have no personal experience with it myself. There are very in-depth technical threads about this.
Unfortunately, as this car has now been discontinued in the US for six years, aftermarket parts, especially big ones like exhausts, can be more difficult to find than they used to be - I believe Mountune and Ford Performance have discontinued their exhausts, for example, and the remaining options such as Cobb and Thermal are very expensive.
1. Edge doesn't tune these cars, they sell something that adjusts the throttle response. This should not be installed on your car and should be recycled as e-Waste.
2. Your primary goal here should be preventative maintenance and familiarizing yourself with the vehicle itself. Fluid changes, wear-and-tear items, etc. This includes figuring out what modifications have been done to the car already (see point 3 below, though as noted we can also help with photos).
3. If you want to tune the car, this is a whole different can of worms. Your best bet on this front is to find a shop that you like and trust and is familiar enough with the Fiesta ST platform that they can tell you what's already been done to the car. Oakos in Sterling Heights or MAPerformance in Wrightstown WI are both reputable shops in your general neck of the woods, though in looking at their website I think MAPerformance may have been bought out by someone else.
Once you find out what has been done to the car, you'll want to find a tuner - there are many good ones, the three most commonly recommended on here as far as I know are Dizzy, Stratified, and Tune+. All of these guys are perfectly competent to tune your car and just depends on who you vibe with. You will want to contact them with your goals for the car - "daily driver but a little zippier?" "track car?" etc - and ask them what parts you should buy and install to achieve these goals. This will save you time, guesswork, and money. These people are professionals. If they say "buy this intake and this set of spark plugs and do not buy this intercooler," your job is to buy those things. If they say "jump," you say "how high?" From here it is a process of having the parts installed on the car and getting a tune installed via a Cobb AccessPort. All of this is going to be expensive. The "how much does that cost?" number is going to have a comma in it.
4. You do not pick up any power on this car with an exhaust unless you have a big turbo. If you are running a straight pipe with a catless downpipe (causing the p0420) and no tune, it is possible that you bought a time bomb and getting either a tune or a replacement catted exhaust should be high on your list of priorities. The stock exhaust is perfectly adequate, it just sounds boring. If you want better sound, get any of the 2.5" options such as the Cobb, Mountune, or Ford Performance, or, if you want the big 3" exhaust, shell out for the Thermal R&D. Most of the others are designed in such a way that they generate so much drone and pressure inside the car that it can actually damage your hearing. The Thermal R&D does not. The CP-E Nexus exhaust is better than most of the other options but not as good as the Thermal. I have also heard good things about the GReddy exhaust, but it's very uncommon and I have no personal experience with it myself. There are very in-depth technical threads about this.
Unfortunately, as this car has now been discontinued in the US for six years, aftermarket parts, especially big ones like exhausts, can be more difficult to find than they used to be - I believe Mountune and Ford Performance have discontinued their exhausts, for example, and the remaining options such as Cobb and Thermal are very expensive.
Thread Starter
#54
Can you explain #1 a little more? How a stock Throttle is different than the one I may have? And why is it hurting my car.
And regarding #2 those are all getting changed eventually. I have drone for sure in my car with my straight pipe. My next thing coming up is bring her into ford, to get a slave cylinder replacement and its fluids checked by ford 2k. Yay.š
And regarding #2 those are all getting changed eventually. I have drone for sure in my car with my straight pipe. My next thing coming up is bring her into ford, to get a slave cylinder replacement and its fluids checked by ford 2k. Yay.š
#1 means itās a device that fools your throttle into telling your car you are pressing the accelerator pedal more than you are, resulting in fake throttle response. Itās common in trucks Iāve found. Utterly stupid tech.
#2 means the downpipe we assume is there is causing your P0420 code and not giving you any added performance just noise. Otherwise there may be a different turbo or tune that we really arenāt informed enough to diagnose.
#2 means the downpipe we assume is there is causing your P0420 code and not giving you any added performance just noise. Otherwise there may be a different turbo or tune that we really arenāt informed enough to diagnose.
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