99 c43 amg, check engine light came on

[benz4life]

Was driving normally, light came on. Nothing changed in car's behavior, drives fine, has power etc.
Where do I start? Advanced auto parts for a free read or disconnect battery 15 min and hope it will clear? Could be O2 sensor?
If I disconnect the battery , will the radio lock ? I don't have the card with the radio code

[SD202]

you can disconnect the battery it will clear the check engine light, But it will come back in one drive cycle if the fault is still being detected. and yes you will need the code card for your head unit if it is still the factory head unit. It would be best to go have the code pulled with a scan tool so you have a general idea of where to start in diagnosing the issue. The car in most cases will act erratically if there is an 02 or MAF problem ( i've had both) my 99 c43 has 213k miles on it now, and all 02 sensors were replaced but when they go bad you will know, My car had a "loss of power" that was felt as a hesitation when i tried to floor it or give it spirited acceleration past 3k rpm. And often times they go bad but dont throw a CEL for many many miles.

[Twichel04]

Go get your codes read. Simply clearing them will not make the light stay off. If there is a problem, the light will come back. Have your codes read, and report back with what they are, then we can help figure out the issue. There are a lot of things that could give you a CEL and not give you any noticeable symptoms. Anything else before reading the codes is just speculation.

As for the radio- Yes, you will need to enter the radio code if you disconnect the battery. If you don't have the code card, call up any dealer, give them your VIN, and they will provide you with the radio code. If they say they can't, or tell you that you need to come in, or pay a fee, call another dealer. They are supposed to provide the information for free, but some dealers try to charge for it.

[benz4life]

P0130 is the code , was saying something about the Bank 1 too .
I think the guy from Advanced Auto Parts it cleared the code too, check engine light is not ON anymore, I drove like 7 miles, sprinted too, didn't came on .
So now we wait to see if comes back on? I don't know if relevant or not, I make about 235 miles with a tank, mixed driving speed and mostly city.

[RemoLexi]

On a lean code you want to look at freeze frame data.

[benz4life]

On a lean code you want to look at freeze frame data.

I guess now its too late, I have to wait for the code to show up again
Also had to google "freeze frame data"

[RemoLexi]

In your case, lean trim code,

Check to see coolant temp

Example : 194degrees .F (warmed up)

Engine speed : 795rpm (idle)

With those clues I would be checking for vacuum leaks next, because a cold engine typically has a higher idle / richer mixture so the trim code wouldn't be noticed if you had a small vacuum leak. Fully warmed up, at idle rpm is where it would flag it.


Those are just clues.

[benz4life]

In your case, lean trim code,

Check to see coolant temp

Example : 194degrees .F (warmed up)

Engine speed : 795rpm (idle)

With those clues I would be checking for vacuum leaks next, because a cold engine typically has a higher idle / richer mixture so the trim code wouldn't be noticed if you had a small vacuum leak. Fully warmed up, at idle rpm is where it would flag it.


Those are just clues.

It just came back on , was heading home from work, so engine was " cold " , 500 ft after I left from work came on... i felt a little lose in power this time, also, at a stop light i felt a little engine vibration . Not gonna sleep well tonight.

[RemoLexi]

You need to check freeze frame data. Just because it came on doesn't mean the problem happen at that moment. It usually stores the problem without you knowing as pending and the next time you cycle the key it triggers the check engine light letting you know something is not right. So check freeze frame data, It may not match your 'cold start' circumstances.

[benz4life]

You need to check freeze frame data. Just because it came on doesn't mean the problem happen at that moment. It usually stores the problem without you knowing as pending and the next time you cycle the key it triggers the check engine light letting you know something is not right. So check freeze frame data, It may not match your 'cold start' circumstances.

I got a bluetooth OBD2 scan tool - for Android and the Torque app ... i'm still trying to figure out how to use all the functions on it. I don't know is i can see freeze frame data on it, that o2 sensor bank 1 still there...
Bad news is that i have some intermittent miss-fires too, on 3 cylinders detected 1-3-4. Should I order 8 ignition coils and 16 spark-plugs?
I cleared the codes, no light now, but i know will come back anytime soon.

[RemoLexi]

Well if you have an 02 sensor code probably heater circuit then there's a good chance you need a new 02 sensor.

Next, your lean codes and now random misfire codes are pointing in the direction of a vacuum leak or bad maf.

Coil packs usually don't fail 3 at a time. 1, yea I can believe it. Also check to see if the spark plugs on that bank aren't filled with oil from a leaking valve cover seal.

[Sulaco]

I would not go so far as to drop a grand on coils and plugs. It's definitely something simple and not-serious.

If OBD is telling you o2 sensor, just replace it. I have had a bad o2 sensor for the last 10k miles on my 98. I can't get the old one off (broke a breaker wrench AND stretched my o2 sensor tool....that sucker is stuck). The car seems to run just fine, but definitely doesn't "feel" as quick as my 99 with healthy o2 sensors.

And this random misfire...is that something you're feeling or just something OBD is telling you?

[benz4life]

Well if you have an 02 sensor code probably heater circuit then there's a good chance you need a new 02 sensor.

Next, your lean codes and now random misfire codes are pointing in the direction of a vacuum leak or bad maf.

Coil packs usually don't fail 3 at a time. 1, yea I can believe it. Also check to see if the spark plugs on that bank aren't filled with oil from a leaking valve cover seal.

P0130 O2 Sensor Circuit (Bank 1 Sensor 1)
Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 33.725 %
Engine Coolant Temperature = 68 °C
Fuel Trim Bank 1 Short Term = 4.688 %
Fuel Trim Bank 1 Long Term = -7.031 %
Fuel Trim Bank 2 Short Term = -2.344 %
Fuel Trim Bank 2 Long Term = 0 %
Intake Manifold Pressure = 7.252 psi
Engine RPM = 1,550 rpm
Speed (OBD) = 54 km/h


End of report.

I would not go so far as to drop a grand on coils and plugs. It's definitely something simple and not-serious.

If OBD is telling you o2 sensor, just replace it. I have had a bad o2 sensor for the last 10k miles on my 98. I can't get the old one off (broke a breaker wrench AND stretched my o2 sensor tool....that sucker is stuck). The car seems to run just fine, but definitely doesn't "feel" as quick as my 99 with healthy o2 sensors.

And this random misfire...is that something you're feeling or just something OBD is telling you?

I don't really feel a loss of power , sometimes , I feel a little engine shaking when I am stopped at a sign , like every 3 sec interval . And fuel economy pretty low... about 235miles on a tank only. city / mixed driving

Can anyone point me to the right part ?
Upstream Left or right? Downstream Right or left ? What brand should i get ? I know most of us trust Bosch ...

Any tutorial how to change it? Should i do it myself? do i need a special tool?

[Sulaco]

I wouldn't worry about anything else until I got that o2 sensor swapped. Use Bosch OEM only. autohausaz.com or partsgeek.com

Bank 1 will be whichever side of the engine has Cylinder 1, I think. Sensor one will be the first sensor (or "pre-cat" sensor)