To clarify, the E85 gas pump had the issue with being extra slow as in delivering about a gallon per minute. Yesterday ( 23 degree's) It started fine, zero smell of gas. Drove all but 2 gallons of the E85 out of the tank. Filled up with rec gas 14 gallons worth-zero ethanol. I figured that combo would put it close to the 10-15% ethanol that is sold in our state, everywhere. (15%) is what all gas stations here sell. It filled just like normal as in a couple minutes. Put about 20 miles on it so far. Started it this morning (17 degrees) and no problem. Yesterday afternoon I tried an old method of disconnecting the battery for 30 minutes just for the heck of it. I doubt it did anything but it couldn't hurt. The cold returns Friday, so Ill see what that brings. It never tripped a code. The temp sensor is a good question. About $20 . Still cheaper than a trip to the mechanic and worth a try.

 

Just a thought, the computer only knows from what sensors tell it, if one is muted by what ever stuff mutes it, then the computer doesn’t have the correct information to calculate. Spot on the O2 sensor, coolant crud on the CTS, does it build up slow enough over time that the computer adjusted based on these parameters, and not throw a code?
A slow fill from the E85 pump, but a normal fill from the gasoline pump, would indicate your EVAP box is working.

 

E85 + freezing + water in fuel = .slow pump. Frozen filters. E85 is hydrophilic.

 

Thanks Donbrew, good explanation. So, would that water in the E85 fuel mess up the O2 sensors or cook the catalytic converter? I’m pretty sure there would be appropriate codes set.

 

It has all the OEM sensors, I believe. 206k on it. OEM exhaust except for a new exhaust manifold which was just installed recently. The engine has always run great. I keep up with the maintenance. Trans fluid/filter change, spark plugs, coolant flush, front end parts as the wear, shocks all the way around. etc. Basically the only motor parts its received was a purge valve solenoid .( and the usual wear parts like spark plugs, antifreeze- engine oil filter etc) With the recent rich running condition, I may replace the plugs again. Not right away though. I need to know that the current problem is solved first. Is it time for O2 sensors and other sensors as part of basic maintenance? Maybe. I'm sure the E85 wont make its way into the tank again but that could have been a coincidence also. We like this little car, I've been offered more than I paid for it and we've owned it 7 years now. ( yeah the price of used cars is nuts) It keeps the miles off my Silverado -2017 has only 12k on it so far.

 

I think the CTS maybe the problem, not necessarily the O2 sensors, they seem to be doing their job.
if the CTS is gunned up, you could clean it off with Scotchbrite or steel wool, or just replace it.
Im not experiencing the problem at this time, I’ve never put E85 in my HHR. But I did clean the CTS when I changed the thermostat and the water pump a year or two ago.

 

Is your HHR the only one ever with a carburetor? Rich at startup/fuel odor is a carb thing, If it is rich there would be a code (P0171/P0172).
Do you always shut the engine off during fuel fill? That is when the computer rests to flexfuel.
Fuel odor in cab could be from cracked flex pipe, cracked vapor pipe, cracked fuel line, loose/cracked fitting on top of gas tank; not flooded injectors.
Cracked vapor line could also cause rough cold idle.
Water in fuel could cause misfire which can damage the cat.

 

It leaks gas from the throttle body area at start up. I cant locate the exact spot because it stops leaking quickly and it dont leak very much. It does this when its very cold out only. I always shut the HHR off while refueling, it has a locking gas cap and the keys come out of the ignition every time. So far I replaced the purge valve solenoid ($30) and the Coolant temp sensor ($20) And now its going into the shop. Called and made an appointment and the mechanic said he knows whats going on and he'll take care of me. Thats all I know at this point. It's 45 degress today so it wont act up but colder temps later this week and he'll have the car to witness the problem. The CTS didnt help. Here's a pic of that. But it was cheap enough and less than 10 minutes to replace.

 

NO gas gets near the throttle body ONLY air, unless you do have the only HHR with a carburetor. Must be leaking from the fuel rail or high pressure pump.

 

There's no high pressure fuel pump. Only the SS has them. So, yeah, the fuel rail is leaking, maybe at the Schraeder valve.