Corolla 2001 had p1345 then p0125.

Hi all!
I'm new in this great forum! Grateful to have the access and post here. I bought a Corolla 2001 S model about 1.5 month ago with a 180K on it. I drove it for 300 miles with no issues but i was not happy about gas mileage about 24-25 mixed but mostly city. I replaced spark plugs, air filter, cleaned MAF sensor and put Lucas upper cylinder lubricant & injector cleaner in a full tank. Shortly after that the check engine light came on and scanner said code p1345. I googled and turns out it is related to VVT system. I started to pay attention to cold starts and noticed there is a slight rattle which sounds little louder at cold start. I can barely hear it when driving and windows open at lower RPMs. I googled and lots of threads suggests replacing the timing chain tensioner to help the VVT system in case the chain stretched and tensioner is lazy. While i was waiting for tensioner (Ordered it online) after resetting the p1345 code from computer i drove about 180 miles then check engine light came back again but this time it is not the was p0125 with pending p0171. I changed the oil too recently and what came out was bad oil. I think the last owner didn't change the oil that often. Anyway today i got the tensioner by mail but now i'm confused cause last code was different. Not sure whats going on at this point. The car drivers & idles fine for its age. The timing chain tensioner is leaking so i will have to replace it anyway but not sure if these three codes are related. Did that Lucas stuff cause all this? Did the owner know about all this and basically cheated me? I hooked my scanner bofer buying and everything was good with no codes. I lost my job and trying to get by during the rona rough time. Any insight will be a relief. Thanks in advance.
Last edited: