2003 525IT-Smog Failed

Took the car for smog inspection- and failed... Technician suggested I change the MAS to begin with. I did, now however; my CEL is on and DTC's are as follows: P0313 -Misfire Det. w/low fuel, P0175- system too rich (bank 2), P1343- Manufactured specific code, P0172 - sytem too rich (bank 1), and P0102 Mass or Volume Air Flow Circuit Low input.

Is this a sign that my sensors are bad? Does anyone know what I should begin with.

Check for vacuum leaks and the MAF. The rest "might" go away if you fix that.

Originally Posted by JaimeRojas

Took the car for smog inspection- and failed...

You 'might' find hints in this (still nascent and unfinished) thread:
- How to diagnose a typical BMW E39 engine misfire (1)

That thread, which is a summary of scores of misfire threads, has all the culprits nailed down; but it still needs a lot more on the diagnostic side.

In addition, to the OP, please post your smog results to this thread:
- Please post your E39 emissions smog test results

Check for vacuum leaks. Buy a small propane tank, and run a long hose off the end; open the valve just slightly, and hold the hose over vacuum components one at a time. If your idle changes, you have found your leak.

Originally Posted by Jimmys 530i

Check for vacuum leaks. Buy a small propane tank, and run a long hose off the end; open the valve just slightly, and hold the hose over vacuum components one at a time. If your idle changes, you have found your leak.

I'll add that to the misfire thread ... but ... may I ask ... (a serious question).

Q: What happens if there is an inadvertent spark while the engine is running?

Does it just 'puff' and go away or is there a boom?

Originally Posted by bluebee

I'll add that to the misfire thread ... but ... may I ask ... (a serious question).

Q: What happens if there is an inadvertent spark while the engine is running?

Does it just 'puff' and go away or is there a boom?

There is no source of ignition under the hood, and even if there was, the amount of propane is very small so nothing will happen. One of my friends is a factory trained tech, and he told me this is the method the dealer uses.