This thread is for those who have experienced a Check Engine Light code 71 for EGR malfunction. I fixed this by changing the fuel filter. This is my scenario:

I am running a 1994 SC400, and about a year ago I got a CEL and I read it using the jumper method which gave me the code 71.

Recently I read a thread about unplugging the MAF for loads of torque. I did this just for fun and then plugged it back in shortly.

Then it seemed it had some difficulty starting where it would have to crank for a bit longer before actually starting. After about 3 weeks, I would start it and within a few seconds it would begin to hesitate and then stall. Usually I would have to start it a few times before it would work.

Then I changed out the fuel filter and the CEL went away, and after a few runs, the starting problem went away. I'm the 3rd owner, and guessing that it has never been changed.

I knew that unplugging the MAF just makes the car dump in lots of fuel and runs extra rich to prevent engine damage so it likely aggravated my old fuel filter problem to the point of not starting.

But how did changing the fuel filter solve the CEL EGR problem?

 

How'd you go about getting your old fuel filter out?

I know it sounds like a simply question with an even simpler answer, but I've got a '93 SC4 with what I believe to be the original fuel filter on it and I'm having a devil of a time getting the nuts loosened on that thing. I've already parrtially stripped the bolts (yes, I'm using the proper size wrench). I've doused the living day-lights out of the joints with PB Blaster + used a heat gun to try and get things loosed up a bit more, and even tapped the nuts with a hammer to try and break the bond. I'd like to take a blow torch to it like any other frozen nut, but this being the fuel line, I don't think that would be advisable.

How'd you get yours loosened?

 

Well, you said you used the proper size wrench, but did you use the proper TYPE wrench? Due to the inherent softness off the metal used for flare nuts, you really should never attack a flare nut without a good flare wrench: http://s7.sears.com/is/image/Sears/0...sm=0.9,0.5,0,0 Unfortunately, once the rounding of the nut has begun, they can be really difficult from then on; even with a flare wrench.

That being said, they are fairly notorious for being difficult to loosen if they are badly corroded regardless of wrench type used. If you search a bit more, I'm pretty sure you can find numerous threads discussing your exact problem. G/L

 

thanks good2go.

I may end up having to just get the entire fuel line replaced.

I know it's a moot point now, but why in the world would Lexus even put this thing in direct and open contact with the elements anyway? Just regular contact with water is bad enough, but in states like Michigan (here) where we use salt on our roads in the winter time it is just plain stupidity to have exposed nuts and threads like this on the underbelly of a car.

When I finally do get this thing changed I'm going to melt some wax over both nuts and threads to keep 'em sealed-up until the next filter change a decade from now.

 

I had to use vice grips to break mine loose, luckily I did not damage the the fittings too much. I started off with the correct size flare nut wrench but they would not budge loose. The vice grips did the job.

 

so ou didn't have issue with the line twisting?

 

the fuel filter is totally not related to the EGR code.