BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > How to fix P420 & P430 codes......

Thread Tools Search this Thread
      09-19-2009, 04:12 PM   #1
cstmx_ryder's Avatar

Drives: A metal box with a roundel
Join Date: Jul 2007
Location: Portland, OR

iTrader: (2)

Send a message via AIM to cstmx_ryder Send a message via MSN to cstmx_ryder
How to fix P420 & P430 codes......

So here's the run down on what happened. I took out my PROcede to take the car into the dealership to get a new fuel pump. After picking up the car on my way home, literally 10 min after driving out of the dealership, I get a 'half engine' light. I-Drive says 'engine malfunction, reduced power'. But I'm not losing any boost or performance(as far as I can tell from my butt dyno, don't have a boost gauge).

Restarted the car and it came back 5 min later. Read the code and it said P420 & P430, something about the catt efficiency is below threshold on bank 1 & 2. This happens every 10 min or so here on after. The last time I got these codes where when I first put in my catless DPs with O2 SIM, and that was about a year ago.......And also before when I got this code, it didn't give me the 'half-engine' light, instead it just gave me a SES light.

I've searched and read the thread regarding this fix, it was something sold in South Africa. It looked like a spacer that pulled the O2 sensors on the DPs out of the way of the gas stream or something like that. But it cost like $350 installed or something ridiculous.

Has anyone else found a solid fix for this? Could it be a bad O2 SIM? I have RR O2 SIM.....

Any input or suggestion is greatly appreciated.


'08 AW E90 335i
PROcede V5 | BMS DCI | RR DPs | ETS FMIC | FORGE DVs | Stett CP | Vanguard | PSS10
Appreciate 0
      09-19-2009, 09:40 PM   #2

Drives: 07 335i
Join Date: Nov 2007
Location: paradise

iTrader: (1)

Send a message via AIM to maui86 Send a message via Skype™ to maui86
so let me try to understand this...when you have your procede in you use its built in o2 sim and it doesn't give any cells. after you took it out and you put a different o2 sim(bms, RR etc.) and now it gives you cells?

if so, its likely bad o2 sims if they dont appear when the procede is on. DP's are a PITA to just swap and see, but it may be worth it given each sensor is an arm and a leg.

IF you dont have your dp's in and running on the stock o2s with NO sims and procede, its likely your o2 sensors could be damaged or faulty. if you installed your dp's and didn't disconnect the o2s from the harness while taking them off or on the wires could be damaged somewhere.

right now my car is in service getting o2's bank1&2 for cyl1-3 replaced since they would give cells every several hundred miles. the car would idle slightly rough(would go to either 500 or 700rpm when trying to stay at 600). they replaced the rear sensor first and it ran and idled better, but now they ahve to replace the front one since the cell is haunting me.


gotta do what i gotta do to get them donuts
04 spec-v: rip dec07
Appreciate 0
      09-19-2009, 11:51 PM   #3
Private First Class
Parachute>Seatbelts's Avatar

Drives: in the rain...cuz its Portland
Join Date: Apr 2009
Location: PDX

iTrader: (0)

He's running rev1 + o2 sims; recently removed his tune for a hpfp replacement and is now getting the P420/P430 codes+ engine malfunction. Probably faulty o2 sensors?
Appreciate 0


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -4. The time now is 01:31 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST