Repair advice

[Avtrill]

Hello I purchased a 2000 rx300 2 days ago from a dishonest person. When I purchased it the guy said there was no engine codes and it was super reliable. The vehicle has 150k miles on it and 2 hours after I paid him I get P0171, and P1130 codes. Now today I drove it and it shows p0300, p0301, p0303, p0305, P0171, p1130 and P0300p, p0301p, p0303p, p0305p, p0171p, p0172p. The only repair paperwork that I found in the vehicle says that a couple of coils were changed and the catalytic converter. Other than that I am clueless. I ordered a Haynes repair manual it should be here tomorrow. Any advice would be greatly appreciated thanks for your help in advance. 

[RX400h]

Take a look here:

Lexus Codes – TroubleCodes.net

By the way, according to California law the SELLER is responsible for having the vehicle smog-checked. 
Did you know this? If you did not and the seller did not verify that the vehicle was smogged, you should contact the California Bureau of Automotive Repair.

Home page - Bureau of Automotive Repair (ca.gov)

[Bykfixer]

Sounds like the seller will need ice cubes in the afterlife. 

Where did you get those codes from? Reason I ask is if you are using one of those $49 readers that was on sale for $29 like I use, the thing starts out telling you what it thinks the issue is followed "but it could be"……

Example, it may say the issue is the code for random misfire, but it may be a knock sensor or xxxx or xxxx or yyyy or zzzzz.  If you are using one of those inexpensive DIY type it would be a good investment to take it to a shop and have them nail down what is really wrong. 

I'm surprised your car isn't running really bad with all of those codes. 

Best regards. 

[Avtrill]

Yes I am using one of those cheap code readers. I am going to take it into my friends work and use a professional code reader.

I found out that the codes with the P at the end are pending. So sounds like a guess like you said. The car ran great until the computer reset. Except for a oil leak on the valve cover everything looked good cv boots etc. After doing some homework I think my best starting point would be to switch the coils on cylinders 1,3 and 5 to 2,4 and 6 to see if the misfire moves. I would like to pull the plugs to see what is going on in the cylinder if fuel is even getting ignited. It is my understanding though that the spark plugs on the fire wall side are a pain to remove. I will give it a shot.

I was aware of the smog law in California but never sure how it actually worked. The title he gave me was the one he got when he purchased it a month before I bought it. So I don't have his name or anything. I tried contacting the app offer up to at least leave him a nasty review but they threatened to delete my account because I was a little colorful with my messages to the seller. I will definitely look into the link you provided to see what I can do if anything. I would love to cost that crooked thief any money I can. I am a believer in karma and think he will get what's coming to him but it can't hurt to help it along a little bit. It's the least I could do. 

[Avtrill]

OK I changed the o2 sensor because I was getting P1130 and p1150. Then codes p0300, p0301, p0303, and p0305 came up. It has been 110 degrees outside so I haven't been able to get much wrenching done. But would anyone know why when I disconnect the battery and the computer resets it runs fine for a while like a couple of days and then starts misfiring and throwing codes? 

[RX400h]

This mechanic investigated something similar:

2000 Lexus Rx300 codes p0301 p0302 p0303 - Bing video

It's about 16 minutes long but is somewhat informative.

[Avtrill]

In case anyone has a similar problem. I had changed the upstream o2 sensor on bank 1 and then replaced all of the coils and plugs. When I pulled the plugs from bank 1 they were pretty caked with unburned fuel the bank 2 plugs looked good. After I replaced everything all of the cel went out and so far so good. I am not holding my breath though because according to the code reader the evap system and the catalytic converter still have not been through enough cycles to read normal. As soon as it does if everything is still OK I will drive it straight to the smog shop and then dmv. I still think I got a pretty good deal on the car though $1700 for a 2000 Lexus rx300 awd with 150,000. It runs really good and just had a new cat and transmission put in. 

[Avtrill]

I had the cel come back on and it was the same code p1130 and p1150. I purchased some mass airflow sensor cleaner and cleaned up the sensor and came across some interesting information about the battery. I was researching why the clock resets itself and learned that the most likely cause is a weak battery. The computer doesn't do well with fluctuating voltage and can be causing my other problems. So when I get the money for a new battery it is at the top of my list. Now I just need to figure out why I don't have any low beams. 

[Bykfixer]

This may sound stupid simple, but years ago both bulbs blew at the same time on an S-10 I drove for work. I figured it was a short or a bad switch or who knows what caused my low beams not to work. "Nah, can't be both bulbs failed at the same time"……but it was. 

Hey, it's worth a try. (Fingers crossed for ya)

[Avtrill]

I wish it was just bulbs that was the first thing I tried. Then fuses and tried to check the relays but couldn't figure it out. Anyone know how to check relays? 

[RX400h]

This guy does a decent job of providing a good overview and test instructions.