BalanBro

Now that you mention it, I vaguely remember a thread about that. Still, it can't be much of a factor considering several tuners turn them off altogether when running LTHs.

RyanC93

Yes it’s not a supra it’s a seat Leon cupra . Same as Audi s3 engine , was running 420 wheel horse power when only weighing 2600
pounds but was front wheel drive 🤮




these codes have came up now.. any ideas, are we still thinking o2 sensors ?

the car smells very rich

RyanC93

Forgot to say the cars revs fluctuate a couple hundered rpm when in park or even neutral

Jasonoff

Likely a safe bet.

How do you like the MK808?

RyanC93

It’s my friends at the garage . It seems good for how cheap is it .

some of them codes come back as crankshaft sensor aswell, so I just hope it’s either one of those sensors

RyanC93

I’ve just ordered 2 o2 sensors and 1 Crankshaft sensor , I think these engines only have 1 Lol?

hopefully these will fix the problem . If not I will have to try the cam sensor aswell.

my car absolutely stinks of fuel now and the idling is worse .. starts at 1000 then 900 then 800 then 700 then 600 then stays at 500 dropping down in 100 rpm increments

hachiroku

did you reset your trims after installing new oxygen sensors? if not it sounds like we found the issue and your oxygen sensors were way off.

RyanC93

The sensors are going in on Thrusday or Friday , I know it’s a stupid question but how do I reset the trims for the sensor ?

RyanC93

I got the o2 sensors finally fitted to my car and disconnected the battery for half a hour. After about 10 minutes of driving my car it suddenly started misfiring badly. Pulled the codes and it was multiply misfires detected , cylinder 1,3&4 misfires ... I’ve already changed the plugs aswell... any ideas ?

BLKROKT

Push the car into a lake, collect insurance, start over with an easier to understand car.

RyanC93

I’ve only had the car a few month! I thought Mercedes were suppose to be reliable .. thanks for the advice though Lol.

the garage saying it could be injectors and I am going to get them tested on Monday. But I don’t see how 3 could fail at once . All the misfires are on the same bank aswell.. surely Something similar must of happened to someone 😫

sventastic82

I would check the wiring going to the coils and injectors.

MB’s are reliable for the most part. Issue usually pop up when you have someone with limited knowledge working on them. (So called European car shops, not trying to offend you.)

RyanC93

I’m just stumped how the car is misfiring so bad and it is only coming with misfire on cylinders and no specific code ..

I forgot to mention aswell just before the car started to properly misfire it was completely dead and didn’t pick up at all between 2 and 4K then after that it took off like it should then the engine light came on. The car was shaking at traffic lights and absolutely stunk of fuel, that’s why my mechanic says it could be injectors . (He has a 760bhp s63 ) and had to replace all of his

ive tried cleaning the maf sensors aswell with no luck 🤨

RyanC93

I couldn’t feel the Misfires before fitting the new o2 sensors and disconnecting the battery .. and when I done that the misfires are much worse ..

RyanC93

Something weird has happened today. I left the car battery disconnected all night then wentto start and the misfires moved to 1,2,3 instead of 1,3,4 and it came up that my tail light bulb was out but it was ok. Has anyone seen this before ?

G_Money

It sounds like someone already did that to his car

sventastic82

I had an issue with misfire on different cylinders on my 2010.
I was never able to feel them but the check engine light kept coming on.

After two weeks of trying to find the root cause and a lot of frustration,
I cleared the codes unplugged the scan tool and put it away.
The CEL didn’t came back on.

Long story short the scan tool caused the CEL.

I used a WiFi obd2 ELM327 Scan tool.

RyanC93

The bulb out was actually just a bulb on its way out and it blew and I’ve changed it . But I Unplugged the maf sensor on the bank where all the codes were cylinders 1.2.3.4 And the misfires went away completely , then once I plugged it back in they started again. I then cleaned it with proper spray and drove around for 30 mins and was all good, then just as I pulled up to my house it misfires again.. would this suggest it is just the maf sensor ?

sventastic82

Switch them. See if the misfire follows the sensor.

RyanC93

Yeh I’ve swapped them around and cleaned them abit more. I drove around for a hour and no codes .. I can tell the car isn’t right just by driving . Feels way down on power after the first 5/10 minutes. Hopefully it comes up on the different bank now. Does anyone know how to test maf sensors any other way ? Thanks

hachiroku

what are you fuel trims reading? also, i assume you reset all codes which also resets trims? if you have a OBD2 Bluetooth/WIFI adapter you can monitor trims as well as MAF readings. if the OBD2 device you currently have is able to output live data, you could display this information as well. report your findings. throwing parts at something without proper diagnosis is the wrong way to do anything. utilize the correct tools which will tell you exactly what the issue is. also, if possible report your vacuum readings at idle.

RyanC93

Yeh I’ve just got a basic scanner what shows the misfires on different cylinders . The garage I’ve been using has an decent scanner but I don’t think it can proper diagnose it , I am going tomorrow to see , if not it is going to the dealers for it. Like you say it’s pointless to keep putting parts on. I’ve changed the plugs, oil and front o2 sensors . And swapped the MAFs over as only 1.2.3.4 cylinders misfiring and it didn’t change to 5.6.7.8 cylinders when I did this . Just don’t know what can cause all one side to misfire 🤔

sventastic82

check the wires

RyanC93

I’m going to get it booked into a electrical garage to get the wires checked to the maf sensor and the coil packs. The dealers has. 12 day waiting time to book car in. It’s just funny how the car is fine for first 10 minutes? If it was wire you think it would do it all the time

hachiroku

If the wiring was damaged you would receive a code for open short or similar.

you really need to purchase a cheap Bluetooth OBD2 dongle and download a free OBD2 scanner app to view live sensor data.

taking everyone's suggestions when they're simply suggestions really isn't helping since you still have not properly diagnosed your vehicle other than reading out misfire error codes.