I am getting REALLY frustrated by this For the second time in 2 days, after clearing the PO171 code I drove the car, and when I got to 30 miles on the odometer, the code popped up. I need at least 50 code-free miles before I can get the car inspected.

To recap, I have different spark plugs, new injectors, switched coil packs when I was getting the misfire on cylinder 2 and for a few times still got that code but it seems ok now, replaced a cracked PCV hose, corrected a crimped elbow hose, and still getting the code. My scanner did not find any faults with the oxygen sensor.

What else could it be????? I am running out of time-inspection sticker expires the end of the month

 

Check the tube from the the EVAP purge valve to the throttle body, Maybe replace the purge valve anyway.
Check the bolts holding the throttle body.
Did the new #1 O2 sensor have sealant on the threads? Did the bung, is it tight?
Check the vacuum tube from the manifold to the brake booster

Stop clearing codes, every time you do all of the testing starts from factory Zero. The EVAP test takes 2 weeks.
I don't know where you got "50 miles with no codes" from. The test is "ready" or not ready" in the I/M Readiness. Federal law says you can pass with 1 "not ready"/"incomplete, that is usually the EVAP system since it takes the longest.
I think somebody misunderstood the directions, they usually say to drive about 50 miles and the tests will be ready.

You are looking for any source of air between the MAF and the #1 O2 sensor.

 

Thanks you very much for all the ideas I will go through them tomorrow.

 

Did you replace this hose?

 

after changing that hose I am able to drive about 30 miles code-free, so it helped tremendously. But there is still something else leaking

 

Here is a pdf from the Shop manual about P0171-P0172

p0171-p0172.pdf

 

Possibly the elbow is damaged and air is getting by?

 

Post #33.

 

Yes this photo is from post #33, see the cracks in the rubber, possibly there are more severe cracks at the other end ? Possibility this elbow needs to be replaced.

I asked about the elbow in post # 15

 

I checked the elbow and it looks fine I even shined a light inside and there were no cracks anywhere. It costs close to $100 so I do not want to replace it needlessly

I ordered the purge valve and it should arrive on Sunday Hoping this will be the answer. The code comes on usually when the car is not moving, like at a traffic light, so motion is not triggering it. And it starts as the T/C light coming on, Then, sometimes the check engine light might come on. But both lights will generally go off after a little while.

History wise, I have been having the T/C light for other codes since I got the car. I immediately began modifying it, back in the So Cal days. K&N oiled filter, (which they said contaminated the MAP sensor), computer tune, Autolite plugs, octane booster pills, etc. But some people were throwing the T/C code with stock HHR's But that code made the car shift hard until it was cleared. And in my case, it generally happened after nailing it or going on bumpy roads.