I've been having problems with my Impala and have searched/heard multiple 'fixes' & suggestions, to no avail.
I have got the SES light on, and took it over to get my codes read (Autozone & Advanced)
Code: P0420 is coming up
Now before I tried anything, I put some Lucas in the gas tank, and it took the light off for about 3 days. And of course it turned off on a Friday evening with no one available to look at my car (for inspection)
Light comes back on, so I decide I'll put more in. Doesn't work this time.
Checked the codes again and 2 codes popped up, P0420 and another dealing with the MAF sensor. Replaced the MAF and only P0420 remained.
Now I replaced the front 02 sensor last year, so I don't think it could have gone bad that fast. I have not replaced the after cat 02 sensor, just due to the fact that the code says its "Bank 1 Sensor 1"
I've checked for any vacuum leaks but couldn't find any.
Some people are telling me to replace the EGR valve; replace 02 sensors; replace catalytic converter; and other various things.
Those 3 were the top 3 'solutions' that I asked/searched.
I tried to take my Cat off to clean it (saw a video saying how) but broke two ratchets trying to do so.
I don't have the money to get a brand new cat installed and was wondering if anyone (with car experience) has any solutions/suggestions.
I just need this light to go away for one day so I can pass inspection and fix it when I get the money
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Other issues that have/haven't been fixed:
Leaking coolant - needs refilled every month - Not fixed
Gas gauge inaccurate - Not fixed
Turn signals/Hazard lights - Fixed
Pinging sound from front driver side tire while making right turns - Not fixed
Replaced spark plugs/wire set - Fixed