I am still battling a number of codes (see list below) - After I changed the purge valve cannister, I noticed immediately a more acrid smell to the exhaust and the exhaust was thicker/smokier/whiter than usual. Is this normal - what exactly is happening here?

I am also, alas, no further along in solving my 9 code ordeal (see list below).

In the last 2 weeks, I replaced the 2 front 02's codes and they cleared for a couple of days then came back. I checked and cleaned all the connections and wiring. I cleaned MAF and air filter. Last night,

After I replaced the purge valve last night -- all my codes went away except for 1884. But 5 codes came back in the a.m., and the four 02 codes came back after lunch today. A new bosch Mass Air Flow sensor is on order and should arrive soon.

In the meantime, any thing else I should be doing? Someone mentioned getting my voltage checked but wasn't sure what exactly I should have checked?

My codes

P0134 - O2 Sensor Circuit No Activity Detected Sensor 1 Bank 1
P0135 - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
P0154 - O2 Sensor Circuit No Activity Detected Bank 2 Sensor 1
P0155 - O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1
P0102 = Mass Airflow Circuit - Low Input
P0445 - Evaporative Emission Control System Purge Control Valve Circuit Shorted
P0448 = EVAP system vent control circuit shorted
P0340 = Camshaft position sensor circuit malfunction Open/short circuit to vehicle supply or earth.
P1884 = (37) CAN message: Engine air intake temperature invalid No apparent effect. On Off.

 

I'd start to look for a chassis ground corrosion issue affecting a certain wire harness, or possibly a damaged wire harness.

This number of codes seems highly unlikely from a diagnostic-point-of-view.. plus some of them which seem unrelated.

For example an o2 sensor or failed injector can obviously impact and cause codes of misfire or rich/lean condition codes..

However an isolated system such as evap emissions, much less a purge valve - should be completely unrelated to engine air temp.

Plus short circuit errors are usually significant give-aways also, as they indicate resistances or voltages that are entirely out-of-range, ie. ground point damage/corrosion or harness damage.

You could check RAVE for harness and "earth" electrical diagrams to see if these systems are shared, but it would probably be far easier to just look around with a good flashlight.

 

When I was chasing my code nightmare a mechanic suggested that tge harness was compromised at the back of the drivers side head.

There is a metal wire bracket that loops around the harness and is bolted into the back of the head. Apparently that can get twisted when head gasket repair is done and chew through the harness.

You wil have to take the upper intake off to see it, but even then it could prove difficult to access for repair.

Also, I believe fuse #2 in the engine bay(15 amp?) controls the O2 sensors and MAF. Check it out.

As you know mine was a ground. Good luck.