Exhaust pressure sensor question

[tbird]

I had some exhaust pressure sensor codes and boost was down from max about 6-7 psi. Before I replaced it, with key on engine off ,streaming data showed 16psi exhuast pressure. After I replaced it I have 14.1psi exhaust.
Same #s when idling. So im not sure if the sensor works in absolute pressure or relative. If absolute than 14.1 would be close to atmospheric pressure.
So I did some testing. If I get boost up to about 15psi the exhaust side only goes up 3 psi. If I remember correctly in the past if I was boosting 15psi the exhaust pressure was in the 30 psi range.

Any input appreciated

[vitalidle]

You could try cleaning it first. Here is a good writeup Welcome to guzzle's Exhaust Backpressure Sensor Cleaning Maintenance Web Page

[tbird]

thanks for the help vitalidle, pulled the backpressure tube and oh looky , it had a hole in it . Got some flare unions and nuts and bent up a new section where the hole was and walla, it works now. Oh yeh, I cleaned it out too and there was a lot of junk that came out but it wasnt plugged.

Also found a boost leak where the line for my boost gauge hooks in so I believe that is why the boost is lower than it should. Still got fix this to prove it out.

[vitalidle]

Good news hope you get everthing worked out!