[lemonpark]

hey guys,

I've been having a problem where my JB4 will change over to Map4 when I go WOT. The SES light comes on once so it's not hitting target boost.

I thought it was gonna be my stock CP and stock DV's causing the issue so I'm ordering a ER CP and Tial BOV next week, in the mean time I got my plugs and coils changed and while we were at it read the codes off the car, I have one O2 sensor code and what surprised us was seeing 2 transmission faults (never seen them before on my car, only the O2 sensor code which has come up before in the past). I have a photo of them and will upload later from my phone. It said something about No. of Cycles - 19, which i think is about the amount of times the JB4 has gone to map4 since i've had the issue

How my friend explained it was that the ECU was sending messages to the transmission but it wasn't going through or something. We cleared the codes after doing the plugs and coils and i took it for a quick drive and SURPRISE! boost was holding at around 15 (i was on map2) and slowly tapering off towards the end of the rev range. I was surprised so gave it a good hammering and it held everytime. Took the car back in to wash and clear everything up. I was happy that the plugs and coils had fixed the issue, but while driving home it went to map4 again -_-

I went to the shop that did my Alpina Flash so that they could have a look at it and I was told that it isn't a transmission problem and that it has to be my o2 sensor.

what do you think the problem is? I have had the O2 sensor fault before and had no problems with my JB4, I've also had the Alpina Flash for about 2 months now and the map4 issue only came up about a month ago after i updated to the latest ISO for my JB4.

Thanks for any info/tips you guys can give me. really appreciated

it also seems that the boost will hold and the JB4 wont go to Map4 after I have one of those coputers plugged into the OBD and read and clear the codes. But it will do it agian after i restart the car. But if i turn on auto delete codes on my JB4 doesn't that do the same thing? (i've driven with auto code delete on for about a week and it still jumps to map4)

[lemonpark]

the codes I get are 511B and CF33

[fazman]

Originally Posted by lemonpark

hey guys,

I've been having a problem where my JB4 will change over to Map4 when I go WOT. The SES light comes on once so it's not hitting target boost.

I thought it was gonna be my stock CP and stock DV's causing the issue so I'm ordering a ER CP and Tial BOV next week, in the mean time I got my plugs and coils changed and while we were at it read the codes off the car, I have one O2 sensor code and what surprised us was seeing 2 transmission faults (never seen them before on my car, only the O2 sensor code which has come up before in the past). I have a photo of them and will upload later from my phone. It said something about No. of Cycles - 19, which i think is about the amount of times the JB4 has gone to map4 since i've had the issue

How my friend explained it was that the ECU was sending messages to the transmission but it wasn't going through or something. We cleared the codes after doing the plugs and coils and i took it for a quick drive and SURPRISE! boost was holding at around 15 (i was on map2) and slowly tapering off towards the end of the rev range. I was surprised so gave it a good hammering and it held everytime. Took the car back in to wash and clear everything up. I was happy that the plugs and coils had fixed the issue, but while driving home it went to map4 again -_-

I went to the shop that did my Alpina Flash so that they could have a look at it and I was told that it isn't a transmission problem and that it has to be my o2 sensor.

what do you think the problem is? I have had the O2 sensor fault before and had no problems with my JB4, I've also had the Alpina Flash for about 2 months now and the map4 issue only came up about a month ago after i updated to the latest ISO for my JB4.

Thanks for any info/tips you guys can give me. really appreciated

it also seems that the boost will hold and the JB4 wont go to Map4 after I have one of those coputers plugged into the OBD and read and clear the codes. But it will do it agian after i restart the car. But if i turn on auto delete codes on my JB4 doesn't that do the same thing? (i've driven with auto code delete on for about a week and it still jumps to map4)

I'm having this same issue on my car for the past couple months. I have new plugs, new coils, new injectors. I'm also back to stock tranny flash, stock CP, no OCC, stock DP. I'm only running ER FMIC, DCI, and map5.

i've been told to get the carbon blasting done from the dealer... so hopefully will see if that fixes it. I had it blasted at 45k miles and i am planning to do it again soon at 95k miles.

[lemonpark]

hey man, me and my mechanic spent a whole day going through everything on the car and we think it's the O2 sensor, in bank 1. I'm getting new O2 sensors put in, need to order them soon and then see how it goes, will get back to you!

[Drill]

Originally Posted by lemonpark

hey man, me and my mechanic spent a whole day going through everything on the car and we think it's the O2 sensor, in bank 1. I'm getting new O2 sensors put in, need to order them soon and then see how it goes, will get back to you!

Was it the O2 sensor??