P0313 Po430 P1093 P2098 check engine light please help!

[Dr. X5]

I have a 2002 BMW X5 3.0 with 140,000 miles on it. The car drives just fine with no problems. I keep getting a check engine light that never goes away. I changed 1 O2 sensor, cleaned my MAF sensor, and did an Evap Smoke test and came up with nothing. i would really appreciate some help on this...

P0313 PO430 P1093 P2098- here are the codes

Thanks

[Weasel]

Sounds like you have a lean mixture fault, I'd check the intake system for leaks. If the intake boot to the throttle body/idle air valve isn't cracking apart it could be the crankcase vent valve. The smoke test works good for the intake system too if you don't see anything off hand.

[Dr. X5]

hey, thanks for the reply... my mechanic already did an evap smoke test and everything checked out. No leaks anywhere. he mentioned something about a possible catalytic converter being bad... but i don't want to spend that kind of money to fix it and it not solve the problem... any other ideas?

Thanks again!

[Weasel]

The lean mixture faults are caused by unmetered air in the intake system, and has nothing to do with the evaporative system. The evap system is the fuel tank ventilation system, if that had a leak it would be different fault codes. One of the other ways to check for intake system leaks is to have a diagnostic tool that reads live data watching the upstream O2 sensor signal voltages and spray down all suspect areas with brake cleaner/carb cleaner etc and when you hit the leak the O2 sensor values stick pegged out at max rich. But the smoke tester is usually easier.

I'd figure out and fix the mixture faults, clear the codes. Then if the cat converter efficiency faults return again you might need to replace them. But I have seen those cat efficiency codes pop up every so often with mixture faults and never come back again.

[Dr. X5]

great! thanks again, im going to run this information by my mechanic tomorrow and i will post an update with what they come up with.

[lo7100]

Any update?

[Dr. X5]

3 mechanics couldn't find out whats wrong with it, and couldn't give me a definite answer that it could be the cat converter, so i called in a favor at the dealer, dropped off the car on Friday for them to check it out, i will update you guys within the next few days with what they tell me...

[Dr. X5]

ok update... dealer said that i need a catalytic converter, and 2 O2 sensors... which i think they just went off what the diagnostic machine told them. which is exactly what my OBD-II machine told me. I still believe there is one thing wrong that's causing all these codes to trip. i have not went in to speak with them yet, i will post another update when i do. i do have one question though...

when my mechanic was replacing the O2 sensor on bank 2, the O2 was stripped, so he welded that hole shut and drilled another hole next to it and put the new O2 sensor. will drilling and putting the new O2 sensor in a different area cause a check engine light trigger? does it have to be put exactly where it was stripped from?

Thanks alot guys, this problem is driving me nuts! the car is driving perfectly fine, and by the way, the dealer quoted me 3,000 to fix both O2's and the cat! haha crazy!

[Wayne's World]

Dr X5 - I've seen your posts all over the net. Have you ever gotten this resolved? I'm getting P0313 and P1093. This issue has plagued me for so long. It's gone dormant for months and then just rears its head again.

[Dr. X5]

hey, yes i finally got it fixed... i replaced my catalytic converter and both my post cat 02 sensors, bank 1 and bank 2... if i were you, i would take it to a shop and have them test out each and every 02 sensor... they put it on a machine and measure when it turns on and off... and that should tell you which one is malfunctioning... i went crazy with mine... even after i changed my cat, i got a code for the bank 1 post cat 02 sensor, i replaced that right away, and my gas milage shot back up and my check engine light was gone... soo good luck!