That seems to be the norm for a combined rating. I get between 18-20 combined and 22-24 on the highway for my '99 RX.

 

At last check I was at 15.8.... not so good for a 99rX... but my 4runner got like 8. Brian

 

Lexmex:
i follow these steps to a T, but now on a cold start it idle rough like it going to die out for about 60 sec then smooth out, did i do something wrong.

 

How long have you been doing this? Sometimes it is still a bit clogged in there and things have to come out.

 

Its been about three weeks since i did the cleaning.
Bat.

 

I find I sometimes need to do the step again, particularly if the oil is old as the crankcase ventilation would really start to cause me issues.

 

Lexmex: can you explain the nature of problem and how related to he air assist hose? Thanks

 

On the air assist hose you need to reclean it and the little black box (has two small hoses going into it) known as a baffle. I'd also reclean the the IACV again along with the MAF sensor. I'd also reset the battery after these steps, because the vehicle's computer is going to assume otherwise that nothing has changed.

 

Still nothing change, could it be possible that the MAF is bad. Because i have to keep my foot on the gas for about a minute then it will smooth out, and its doing it now even when its hot.

 

What are the RPM numbers you are getting in Park and Drive with your foot on the brake at startup?

 

When i start up it die out, i have to keep my foot on gas to keep it running, it run rough like it gone to die, RPM 2/300 then after about a minute of rough idling it smooth off and RPM around 1000/1100.

 

I'd run some fuel injector cleaner in your gasoline next tank full. The air flow would be practically immediate through the throttle body and the IACV and even its hoses, but the one constant that won't hold true is fuel delivery and I can see any clogged injector causing the issue mentioned above where it takes about a minute. The only other possibility offhand is a leak anywhere on the IACV or one of the hoses...I'd also check the rubber o-ring underneath the MAF sensor.

 

I've had the 441 code for a couple years and have been able to get it through the NY emissions inspection. The computer doesn't check the evap system if the gas tank is over 7/8 full. Here is what to do. Fill the tank then clear the code. Drive the car for about 30-40 miles and keep the gas tank full. The CEL should stay off. Driving will reset the monitors in the computer except the evap system. In NY for a 1999 car, 2 monitors can be incomplete and still pass. Hope this helps.

 

I wanted to ad my 2 bits about cleaning the IAC valve.
First of all, Thanks LEXMEX for your great picture DIY's. I've used a couple of them and found them VERY helpful. Especially the door panel removal and aftermarket actuator installation.

With regards to the screw removal on the IAC valve motor...... On my 2000 RX300, the screw heads were already buggered up a bit. No screw driver would seat in it well even tapping it with a hammer. I was fretting over using my electric 1/4 inch impact, but seated with a new bit, it broke them free easily and immediately.

So for those wondering if it is a good idea or bad...... My experience was good. I probably wouldn't have gotten it off any other way.

Thanks again!

Dorian

 

The combined mpg for my 99' RX is around 20-21. The funny thing is I think its fuel economy actually improved a little as the car aged (I bought it new).