Funny LOL

 

Code 0420 back. 218k .I just erased it for now. I'll see how long befor it pops again. Thinking to sell it soon. Maybe. It's been a trooper for sure. It's starting to rust out also. Can't stand the price of something newer though. I have options, drive it till it's worth nothing or sell it. I may just drive it as is.

 

If the code is back, it’s probably the catalytic converter clogged

 

Converter is only 7 months old and maybe 3200 miles. The rest of the exhaust system is louder than the stock system. Car runs good though. A clogged converter would more than likely affect performance. This replacement system is just okay IMO. It Rattles a little at idle, although everything is tight and not hitting anything. Im guessing the muffler has a loose baffle. Slip joints were welded up, not clamped. All new rubber insulated hangers. Can an 02 sensor be fussy with this system? Never ran E-85 with this system. I might add a can of Seafoam to it. I usually do that once a year. Overall this car has been a good one, owned it going on 10 years. With snow tires on, it plows thru the snow very nice. I'll drive it as is for now and see how long it takes for the code to return.

 

Try a Seafoam treatment

 

Drove it with the Seafoam in it for a quick trip. Erased the code. So far its code free. A couple of longer trips also. So far its going good. My wife does not want to part with it. She loves this little "suv/truck" It's always had a steering wheel vibration at 58 to 61 mph and I have 2 separate sets of tires, winter and summer. I figured just to speed up thru those speeds. I replaced the front wheels bearing more than once. Brake disc's, even tried new cv axles. Im guessing the electronic steering has something to do with it. That is its only flaw. Just swapped summer tires onto it and they are so much quieter than the winter Glacier Grip II tires.

 

Most likely inner and or outer tie rods

 

LCAs. EPS does not cause vibration.
P0420 could possibly come from bad/wrong #2 O2 sensor.
Do a Seafoam treatment through the Throttle Body and directly in the cylinders. Spray it in the TB with engine running watch smoke. Put a few oz. in each cylinder let sit over night then start up and watch the smoke; that cured my oil burning problem.

 

LCA's replaced, no change. Tie rod ends seem tight also. In high school, I had a front end alignment class. Got an "A" in it. Car had an alignment done on it about 8k ago. I told them what the symptoms were. It all checked out okay. Oh, new struts too. It's done this from the day I bought it (155k) now 218k. Vibration isn't significant, its kinda slow, more like a light shake. I appreciate all the suggestions though.

 

The ONLY adjustment available on a stock HHR front end is toe. I doubt your high school covered McPherson strut alignment.
Not many alinement guys know what to look for on a HHR.