Mskhan18

While travelling from Austin TX to Dallas TX, CEL came on. Car ran smoothly - no loss of power, no hesitation, no rough running, everything worked still CEL on. Stopped at an Autozone and they ran code scanner to detect P0302 P0304- I couldn't stop so I kept driving and reached home - had kids in the car with me and was travelling late, 8 pm plus.

Short story, today I've done the following
1. New Spark plugs
2. Cleaned MAF
3. Changed coilpacks to different cylinders to detect faulty coil pack

Nothing changes. the whole list of codes still displays (and I have the same list in pending codes- what ever that means, I'm now using Scantools software to detect codes). I am unable to clear codes using the software.

Also, I replaced cylinder 2's coild pack with 1's, and 4's with 5th, but it sill shows P0302 and P0304 along with P0300 - so my guess is coils are fine.

Can someone help here?

I'm inclined to order MAF (Stealer says $500 plus, Amazon says $110) but I don't know why I'm ordering it ??

HELP SOMEONE !

EDIT: Its 2009 E350 sports. 71300 miles. Had 70k service done at 68K miles. New air filters and everything else. Didn't do the recommended brake system flush but rest all was done for service D.

Mskhan18

I've now also put in Techron Fuel System Cleaner and filled up with fuel. Car still runs fine but I can't get the CEL off and get the same DTC.

Any suggestions?

Mskhan18

So ....... ordered MAF from amazon ..... Guess I'm throwing money at the problem and see if that will resolve it!

RichM

Did you move the wires with the coil packs? The coil packs may be fine, but the wires may not be. The pending codes relate the the MAF, but as pending codes they are not setting the CEL. Not familiar with Scantools, but any handheld OBD2 reader will be able to erase these codes.

Mskhan18

1. I didn't move the wires just the coil packs.
2. Scantool is an OBDII software and equipment that I bought a while ago and have been using. I've have been able to clear codes with this before - my current argument for not clearing the DCTs is that since I have pending codes they become active as soon as clear the active codes. (that's what I'm telling myself is happening - may not be true at all)
3. I thought if I fix the problem DCT should clear out but since I'm not able to resolve the problem they keep coming back. I've ordered MAF because i think it might be causing the misfires. I have P0302 P0304 and P0300 in which P0300 is stating misfires in the whole system and it is just the cylinder 2 & 4 register first before P0300.

Thank for your suggestions.

Plutoe

All the P0xxx obd codes relate to emissions issues and when you cross reference with the MB fault codes---the 0300=missfire, 0304=damage to the 02 sensor,0302 damage to the 02 sesor---

Coils and plugs give different faults therefore you wasted your money, furthermore don't go an purchase a MAF--thats a differentset of faults.

From DAS Xentry you have help steps for those faults and they all suggest injector and compression issues with cylinder 2 and 4 and I suspect that you gas milege has gone down.

MY two cents----Get a good scan to determine what is the issue with 2 and 4.

Mskhan18

1. According to engine codes site, O2 sensor might be one of the issues for P0302 and P0304. I've also got P0300 and when I moved the coils the codes didn't change - so I'm inclined towards Misfire
2. When i removed the MAF, engine ran fine so I connected it back and it sill ran fine, however, I do have P0113 along with P0101 and P0103, which is again, misfire

So after, CEL was fired, i drove 200+ miles without incident and got 23.4 mpg which is what I usually get on highways (between 23-25 mpg when I drive, better when my better half drives). I can't notice any difference in performance, there is no hesitation, no shudders nothing!

Appreciate your suggestions.

Mskhan18

UPDATE:

CEL is gone. After coming back home I tried to check the car again. When I started, CEL was off. I connected my software and it reports thats the codes are there but CEL is off. When I clear the codes, they go away but reappear after a minute or so BUT CEL stays off ??

Mskhan18

UPDATE 2:

Okay this is confusing now. I've received and installed MAF and the result is that no codes are detected and CEL is off. The last detected codes are now in the "Stored Code" section.

BUT ..... I tried on the original MAF and it sill worked fine - so MAF isn't the issue here.

The only other thing I can think of is that I might have filled up with bad fuel during my travel and it caused the misfires. On my return, I put in Techron Fuel System cleaner and I think that now it has cleaned the system and so no CEL is displayed anymore .... but my OBD still says "car is not ready for emissions testing".

Confused.

samaritrey

How long have you driven the car since the last clearing of codes?

Mskhan18

0 Miles. But kept the engine running for around 20-25 min when I was reading codes and trying to make sense of it.

Plan to use it tomorrow and have to fill up gas as well - so will be driven about 30 miles.

samaritrey

To get the car to be ready for emissions you have to drive it like 30-100 miles from my understanding. Don't know if idling is enough.

Mskhan18

I understand. I wasn't driving the car because I wanted to get it fixed first. It's not due for emission until December and had recently gotten the car serviced etc. I planned on using it today but then skipped again. Now I'll just drive it to get some fuel in it (3 miles round trip) and maybe drive it more over the weekend and see what happens with it after that.

Thank you.

Mskhan18

So .... updates!

Have been using the car. CEL keep going ON/OFF and now has a particular habit. As soon as fuel goes low to about 2 bar on the indicator, OR I fill up the car with gas CEL turns ON with the same codes. Whenever that happens, I put in Techron Fuel System Cleaner and CEL goes off in about 1-2 miles. After that the car runs fine without any problem until the fuel goes real low or I fill it up again.

I posted on another forum and on the recommendation of a member on that forum, I did the Compression test. Turns out Cyl 2 is off. { Cyl 1: 160 psi, Cyl 2: 115 psi, Cyl 3: 160 psi, Cyl 4: 158 psi, Cyl 5: 155 psi, Cyl 6: 160 }.

So now am going to trouble shoot it more and see what is happening with Cyl 2. I hope it is something simple. (read cheap) OR is covered under extended warranty! If its not I'm going to charge $1 from every forum member who reads the post and doesn't reply

Mskhan18

Hi,

Can anyone here suggest an Indy shop in DFW area who can do a leak down test on my car's engine?

plz let me know I'll not charge you the $$$s as stated in my last post.

cmriv

Sounds to me like you need a cylinder head....

Mskhan18

You are correct. Car at dealer for cylinder head replacement. Don't plan to keep it any more after this 😓