Ion goes into a “limp mode”
 

I have a 2005 Ion with 150k that is starting to nickle and dime me. Most recent issue is if I baby the car throttle it drives fine. If I get on the gas hard to say pass someone of get up to speed entering the freeway, I lose power, check engine light starts blinking, and RPMs climb up to 3k. I have to pull over, shut things down, and restart it to reset.

I have had a check engine light on for a while throwing the catalytic converter code. I paid it no mind because the car was running completely fine for close to 2 years with it. I assumed it was a bad sensor that I did not want to touch because of corrosion. I also recently noticed a fuel line leak, that I will obviously fix ASAP.

What does everyone think? Is this air in the fuel line from the leak that I just noticed? Catalytic converter clogged and needs replaced (or removed 😉)? or just bad exhaust sensor?

I have read there is a sensor before and after the catalytic converter. I only have one before it. Also, I had to replace the ECM last year because the car started acting like it was possessed (blinking lights, erratic shifting, RPM changes, etc). I replaced spark plugs and fuel injectors several months ago. Thanks in advance.

You had a cat code or sensor code> If it was the cat code your cat has been bad and is likely causing some or all of your current problems with the exception of the fuel leak. BTW air doesn't get into the fuel line when it's running as the fuel is under pressure.
Time to do some testing. No emissions in your area. Bust the honey comb up and clear the cat bed. Make sure the muffler is not plugged. Did it fix it?

P0420

I agree with Gary. I'd drop that cat, take a piece of rebar or some strong steel pipe and chunk all of that crap out of it and put it back on and see what happens. I can't believe you'd ignore a check engine light for two years! That's just asking for trouble like you have now.

You can't throw a p0420 without both a front and rear O2 sensor. The front one detects the amount of oxygen in the exhaust and the rear sensor after the cat plays the role of policeman, making sure the amount of conversion of exhaust gases to oxygen is occurring properly. PO420 catalyst below efficiency is thrown when the two sensor readings are compared to each other and it is determined that the cat is not doing its job.

Depending on when they've or if they've been replaced, the front sensor usually gets poisoned around 100k. The rear one gets valved as well
but not as quickly.

I've had multiple instances with my saturn s cars throwing PO420 when in fact one of the O2 sensors was fouled. Replacement took care of the code and the cat is still in the car.

Measuring the back pressure at the front 02 bung should give you an idea as to whether your cat is clogged.


Notwithstanding all of that, your vehicle is exhibiting issues consistent with a clogged catalytic converter. A flashing service engine light means and active misfire is occurring