Max boost before code

[kblranch]

Does anyone know what the maximum boost you can run on a 2004 (305/555) before it sets a code for over boost? If I take my EZ off and leave the boost elbow on do I run the risk of setting off the over boost code?

 

[JVolpe]

From what I have read the EZ does not do real boost fooling, of course my normal "ignorance" disclaimer applies to my reply.

 

[Jeff Clark]

The EZ must do something b/c I was hitting 35psi with the boost elbow in and I wasn't setting any codes. I've had the EZ out for the last 4 weeks b/c it quit working and I haven't taken the time to send it back. I still have the elbow in, so I've been careful not to let the boost get too high. I've hit 27-28 a few times (not sustained) without setting any codes.

 

[JStieger]

Does anyone know what the maximum boost you can run on a 2004 (305/555) before it sets a code for over boost? If I take my EZ off and leave the boost elbow on do I run the risk of setting off the over boost code?

I think it's ~22 psi. Ever since I got my ECM reflashed to rule it out when trying to solve my high-pressure fuel system problems a month ago, I have popped this code (P0234) no matter what boxes that did boost fooling were installed. No affect on driveability yet though.



If you take the EZ off and make sure you don't go over 22 psi then you shouldn't pop any codes.

 

[kblranch]

It must be over 26 pounds as I have hit that without setting off the code.

 

[DLeno]

my best guess here is that there is no simple threshold beyond which you get a code and below which you get no code. Its probably more complex, involving time spent at certain boost levels, engine conditions during that time, etc. I've hit 25 psi too, bone stock no fueling box. But thats where the wastegate is too, on this truck. They probably do something similar to the 2nd gens -- if boost gets too high, the ECM defuels and then re-checks boost. if the ECM's efforts are not succesful in reducing boost it will THEN set a code.



But if you monitor the behavior of boost foolers (in fueling boxes) they all stay at about 25 psi or lower -- capping boost (seen by the ECM) at that value so that the ECM doesn't see higher than that. thats just the design of this truck -- it wasn't intended to go beyond that point for any useful period of time.

 

[nickleinonen]

bone stock fueling on my truck, and i have seen 26psi or just a hair above it and no codes for overboosting...