Hello - I am a newbie here so this problem may have already been discussed. The engine light comes on on our 94 Previa with 135K miles. The diagnosis indicated that it was an emissions problems, and most likely an EGR valve and/or modulator that is getting gummed up with carbon. It is very difficult to get to those valves to replace them, since it requires lowering the engine ($$$). My questions to all of you who have dealt with this:<br><br>1) Has anyone been able to solve this problem without going to the expence of lowering the engine? (i.e. using a gasoline additive to reduce carbon buildup in the EGR. If so what brand?) <br>2) Are there any special tools that can let you get to the EGR without lowering the engine?<br>3) If you must have the engine lowered, what other parts of the engine should be serviced/replaced at that same time?<br>4) For those of you who have lowered the engine, what was the cost?<br><br>Thanks much! John (Spokane, WA)

I have a 91 Previa and I think it is the same engine. You do not need to lower the engine to remove the EGR valve. All you have to do is to remove the EGR modulator and the vacuum tubings assembly by removing two mounting bolts on top and several small vacuum hoses. Disconnect the exhaust tubing, two coolant hoses, and two mounting nuts on the EGR and it comes straight out

Had the same problem on my 94 Previa. The problem is not with the EGR valve but there is a channel between the throttle body and the EGR which becomes clogged. My dealer cleaned the channel and the light has never come back.

What tends to happen is that the valve fails and leads to exhaust gases continuously being recycled which is not good for performance. It also leads to the inlet manifold etc getting gummed up with nasty black stuff especially on older vehicles.

They are fitted to some 300TDi's as well.
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Tips always check the door hinge seal

how do you read the flash codes on the previa? im having trouble because both check engine light and oil light binks when jumping diag ports .... can you help? thanks

Hi, I just rolled in today and would like to thank 94 Previa for the advice regarding the EGR problem which has code 71(?)
I followed his advice and solved the problem. You dont need to pull out the engine, just take out the throttle body and EGR valve, clean out the passage from the EGR hole all the way to the inside wall of the intake manifold. While you're at it, might as well clean out all the vacuum holes on the throttle body by using a solid wire and a lot of compressed air. Also , does anyone here is selling a speedometer cluster with tach on it? I have a 94 previa and I really want one for my van. Thank you.