Driving our van we suddenly got a check engine light and the engine noticably started to run rough. It seems like it runs rougher at lower speeds but at highway speeds improves some. We thought for a minute we got bad gas. No stalling though. Hooked it up to OBD reader and I literally have over 200 error codes. Most noticeable is multiple cylinder misfires and a lot of powertrain issues but some other issue. I’ve been chasing my tail trying to figure this out. Checked battery and alternator. Replaced spark plugs which were very worn. Replaced bank 2 downstream O2 sensor because I was getting no data from it. Checked catalytic converter and it is fine. Have looked over most wires and have checked most sensor connectors and checked with a multimeter including MAF and CPS. Nothing.
What really gets me is Im getting many sensor low/sensor high, voltage low/ voltage high. By trade Im a biomedical technician and I deal with many computers and DC current issues on medical equipment. This seems like either a short somewhere causing interference I cant find or a bad PCM or a compression issue. But if compression, is it common to see so many sensor and ancillary errors? Just wondering if anyone else has seen a mass malfunction like this and what could cause it? Im thinking