Does the Ionization Sensor have anything to do with error code p0325? Does the IS detect knock sensor malfunction?
I have a 2006 SAAB 9-3 4cyl 2.0T with a B207R engine. (8th VIN digit is a Y). I'm in the USA. The VIN indicates the car was built in Trollhatten, Sweden.
A mechanic is telling me the Ion Sensor is bad and replacing it will make the code go away. I'm not so sure.
History is that that mechanic replaced the ECU because of an A/C issue. Turned out that that ECU was a used one even though the bill was for a 'NEW ECU'. Only after the replacement, did the p0325 came up along with p0300 and p0172. That mechanic who did no diagnostics told me that it needs new spark plugs and coils. I didn't do that because he ran no diagnostics and his suggestion was just a 'that should work.'
Another mechanic ran diagnostics and told me the problem was that the ECU is bad and needs replacement.
I replaced the plugs with factory recommended NGKs, which temporarily eliminated the 3 codes, but p0325 came back.
I replaced the ECU with a used one and had it reprogrammed. Don't ask if it was reprogrammed or just married to the engine as I don't know. Problem there was that even though the ECU had the same part number, it was from a 2005. That created other codes I need not go into since they are unrelated to engine performance.
Sued the original mechanic who agreed to make things right.
I bought another used ECU from a 2006 with the same engine. Donor vehicle also had a Y in the VIN. He is installing this ECU and the original programmer will program this one. I expect (hope) this will eliminate the p0325. But now the mechanic says the code comes up because the Ionization Sensor is bad and needs to be replaced because the Ion Sensor also detects knock. The engine runs fine despite the codes.
So, back to the original question: Does the ion sensor have anything to do with the p0325 code and would a bad IS throw a code for engine knock sensor malfunction?