E46 power loss

[hotimportknight]

Recently while driving my car too and from school (2000 323ci 5 speed manual) it loses a lot of power and the check engine light comes on. Usually when it does this its hard starting, ie it cranks for a long time compared to normal, then it runs with very doggy power. I made a correlation to it usually happening when I'm running lower on gas, but today this wasn't true, I had half a tank if not more of gas). It'll try to describe how it feels driving... You take off like usual in first and it just doesnt feel nearly as powerful, almost like driving my 96 metro, just steady amounts of no power. Where normally once you hit 2,000 rpm or so you can feel the variable timing kick in and its got a boost of power. But when it does this its just a constant doggy acceleration, and some times the service engine light is on... Does anyone know what this could be? It will usually do it, then not do it a little while later, like it fixes its self. I'm thinking fuel filter? Does anyone else have any ideas? Its got brand new spark plugs and all that stuff, the NGK's with 4 prongs so it shouldn't be that. Please let it not be like the vanos controller or ECU or something! If anyone has any ideas please let me know, I live 2.5 hours from the nearest BMW dealer and my shop I have access to doesn't have a BMW adapter for a scanner tool of any kind to read the code.


And also, just to throw it out there, what would you go for if you had 25k, well 10k for my car and 15k financing, to get the coolest car possible? I'm thinking a used 2003 M3 with 40-50k miles when they drop to that price range, right now they are kinda rare for that price, but I'm thinking when the new M3's start being more available. Otherwise I've seen a FEW lotus elises on ebay and stuff for under 30k... Otherwise what are good options for a 21 year old who's extremely into cars, I love my 3 series but I need something with more power and such, something that looks nice and preforms nicer.

Thanks in advance for any input.

[gixerdave1983]

could be a whole list of things to be honest mate, you really need to get the codes read to pinpoint it a bit more

[hotimportknight]

Thats what I'm hearing around online. I'll take it to Motorwerks BMW in Minneapolis this weekend before or after I fly out and see what the codes are saying. Then I'll fix it myself.

[Chet]

Mine did the same thing... Check the Mass air flow meter. it might be dying on you.

Mine would show the check engine and the /!\ light at the same time.

[iseedipp]

have them pull the code, if it is the maf use crc maf cleaner. It could possibly be your vanos going out.

[Manolito]

The hard starting and poor performance at low RPM suggest it is not VANOS.

Mass airflow sensor is a suspect.

Your fuel filter thought was also good, but would not likely cause hard starting. On an e46, the fuel pressure regulator is in the fuel filter, so you actually have two suspects in one part. If it is several years old, a new one is a good maintenance item anyway, I would put one in. I posted directions here.
Cabin_Filter