Colorado Front Range Emissions help

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Maryland
We are trying to get the 1994 80 Series through Colorado Front Range Emissions and are having issues. The car has 240k miles and has recently been baselined. Oil is 15w-40 with under 500 miles, it was burning significant amounts with 5w-30 on the trip out but shown no consumption with the new oil Delo XSP.

Bank 1 O2 Sensor is new, bank 2 is 40k miles old and tests out fine. There is an intermittent CEL 25 that I suspect is wiring.

The car is un modified with standard wheels and tires and the test is a rolling treadmill.

The first test she rolled right into the bay without stopping the engine. It passed tailpipe, but failed on the gas cap (which baffles me). On the second two runs it failed on CO. In the second run she shut down the engine waiting in line. The last run was supposed to be on E85 mix but there was some confusion and it was only 85 regular. The car was run for about 20 minutes prior to entering the station an left on in line.

What we have done: smoke test - no leaks, confirm timing a 3 eg BTDC, added 6 gallons of E85 to 1/4 tank of regular.

Any insights? Here are the results as well as a graph from Run #2

I have added photos of the 3k mile old plugs from a compression/leak down test run about 100 miles ago and after the trip cross country.

1758037470145.webp



Emissions.webp


plugs.webp
 
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I have issue with pair valve staying open when it should close. Pumping air in to exhaust giving oxygen sensor "bad" info.
 
I have issue with pair valve staying open when it should close. Pumping air in to exhaust giving oxygen sensor "bad" info.
I thought I had been through the PAIR Valve per the FSM. I will have her look at the O2 sensor information on the ToyoOB1 device.

Thanks
 
My wife wants to move back to colorado. We used to live in Fort Collins. But I refuse to live anywhere on the front range with air care. My 80 runs way to well with the PAIRS and EGR deleted. :hillbilly:
I do have a full PAIRS system that was working fine when I took it off though. If that turns out to be the case. No idea what they are worth right now.
 
Ok, one challenge is while she works for a guy who is a long time Audi mechanic, we do not have an established relationship with a Land Cruiser facility in Denver. We know of several, but I am hesitant to shotgun this from experience in DC. Colorado offered a diagnostic service a we were there this morning and got the attached report.

By way of background, the outboard O2 Sensor is new Toyota. I have a new inboard O2 sensor and hardware as a spare. The current inboard sensor is 7 years an 33k miles old it reports no errors. The outboard had a heater circuit fail.

I had a period with Code 25/26 that I thought was resolved by cleaning a bit of a nasty accumulation on the connectors with vinegar, alcohol and contact cleaner. On the trip out to Denver code 25 began to appear intermittently but with increasing frequency.

VAF was tested per FSM and watching the airflow reading change with RPM on my little ToyoOB1 display. It seemed fine.

I have no idea on the Cats other than after riving around the rear is hotter than the front per my infrared thermometer.

I am thinking my starting point ought to be to replace the inboard O2 Sensor and both connectors as well as check the sensor wires.

Justin the inspector is suppose to give me a call.

Any other thoughts?

CO_Emissions Report.webp
 

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