04/04/2026
A complete exhaust restriction is relatively easy to diagnose using the exhaust pressure gauge.. 2.5 at idle is already a red flag and then it buries the guage whenever the vehicle is revved to 2500 RPM..
Checking for partial exhaust restriction however is an entirely different case.. in most cases, you'd need an in cylinder pressure waveform or a pressure transducer in the exhaust to detect a partial restriction.