Check engine light came on and has the code P0446 for a 1999 Lexus RX300. What should I do first?


Asked by Sep 05, 2013 at 03:08 PM about the 1999 Lexus RX 300 Base AWD

Question type: Maintenance & Repair

I just bought a 1999 Lexus rx300
2 days ago and I took my sister for a
ride in it the night I bought itand I drove over a speed
bump going very slow and next thing
I know the check engine light is on. I took it to an auto part store and they said the code is a P0446 and they dont carry the part so I need to go to the Lexus dealership. I was hoping there was something I could do first to see if I can fix it. Someone said it may be the wrong size gas cap? I dont have a warranty and am hoping this will not be an expensive fix!

6 Answers

P0446 Evaporative Emission Control System Vent Control Circuit Malfunction There will be no obvious symptoms to driver, other than Malfunction Indicator Lamp (MIL) illumination. Causes A code P0446 could mean one or more of the following has happened: Faulty vent valve Open, short or excessive resistance on Vent valve control circuit Blockage of vent valve Bad PCM Possible Solutions With a P0446 OBD-II trouble code, here are some things to try: Replace Vent valve Repair open, short, or resistance problem in control circuit Repair open, or short, or resistance problem in power circuit Replace PCM

5 out of 5 people think this is helpful.

Doesn't look like a DIY Nagle. But not a MAJOR expense

4 out of 4 people think this is helpful.

From another site: It very well could be your gas cap. Missing Fuel cap - Incorrect fuel filler cap used - Fuel filler cap remains open or fails to close - Foreign matter caught in fuel filler cap - Vent control valve harness is open or shorted - Vent control valve circuit poor electrical connection - Faulty vent control valve

8 out of 8 people think this is helpful.

The same thing happened to my RX300 had to replace the gas cap.

8 out of 8 people think this is helpful.

Happened to me on my RX300. Vacuum hose on the back of the air filter box was not replaced after the air filter was replaced. I have it on again so hopefully an easy fix. Also, the check engine and vsc lights don't come on until about 100 miles after the hose was disconnected. Very common.

6 out of 6 people think this is helpful.
Tony Budz

Just had the little engine light come on, checked gas cap it wasn't tight at all, manual says drive 3 times to make it go away, if not get checked at Midas or something.

2 out of 2 people think this is helpful.

Your Answer

Add photo

Related Questions

RX 300

Looking for a Used RX 300 in your area?

CarGurus has 1,066 nationwide RX 300 listings starting at $2,363.


Search Lexus RX 300 Questions

Lexus RX 300 Experts

#1 Rx300_21001
Reputation 1,680
#2 John Orlando
John Orlando
Reputation 910
#3 mrsvirtuous
Reputation 600
View All

Related Models For Sale

Used Toyota Camry"
1,653 Great Deals out of 98,470 listings starting at $895
Used Toyota RAV4"
1,220 Great Deals out of 48,978 listings starting at $2,495
Used Toyota 4Runner"
384 Great Deals out of 18,843 listings starting at $2,400
Used Lexus ES 300"
15 Great Deals out of 1,182 listings starting at $1,500
Used Honda CR-V"
1,656 Great Deals out of 81,771 listings starting at $1,695
Used Mercedes-Benz M-Class"
317 Great Deals out of 6,183 listings starting at $2,950
Used BMW X5"
551 Great Deals out of 15,546 listings starting at $2,995

Used Cars For Sale

2003 Lexus RX 300 Base AWD For Sale
4 Great Deals out of 89 listings starting at $2,799
2002 Lexus RX 300 Base AWD For Sale
4 Great Deals out of 169 listings starting at $3,000
2001 Lexus RX 300 Base AWD For Sale
157 listings starting at $3,850
2000 Lexus RX 300 Base AWD For Sale
9 Great Deals out of 187 listings starting at $2,363