When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The check engine light is on and I had a friend do a diagnostic to find out the problem code. I/we removedEGR valve and cleaned it and also cleaned inside where it mates up to the intake manafold. The CE still is on. I'm now thinking the problem might be the EGR temporature sensor, and it may need replacement.
I called the dealer and they want $153 for that little part.
Without going into a lengthy detailed explaination, there are several items that can make the code 71 reappear. Egr temp sensor input, both vacuum modulaters, any leaking or cracked vacuum lines. All need to be properly inspected. What did the dealer say it was? Which LS400, 1990/1993, has the problem? What little part are you talking about? If the dealer already looked at it why don't you just buy the part and put it in?
Originally posted by DevilDog Without going into a lengthy detailed explaination, there are several items that can make the code 71 reappear. Egr temp sensor input, both vacuum modulaters, any leaking or cracked vacuum lines. All need to be properly inspected. What did the dealer say it was? Which LS400, 1990/1993, has the problem? What little part are you talking about? If the dealer already looked at it why don't you just buy the part and put it in?
DD
Hi Devildog, I hoped you would chime in. The problem is on our 90. I had an independent hook up and tell me what code/problem was causing it. My mechanic removed the EGR valve and we thouroughly cleaned it and the opening where it bolts to the intake manifold(which btw was partially clogged with an encrusted mess). My mechanic felt, if this didn't correct the problem, the next step would be to replace the EGR Temporature Sensor. That was the lil $153 part I was speaking of.
What do u think Devil? You really helped me a while back on diaognosing that broken wiring problem with the trunk having a scissoring effect on that wiring bundle back there. You nailed that one!
Unfortunately your independent does not know how the egr system works. Or he could simply check the system and tell you what is wrong. The proper procedure involves using a vacuum guage. If you already cleaned the egr passage and the check engine light still comes on. The your problem is probably the egr vacuum modulator. It's the round vauum device just before the egr. It has two vacuum lines into, then one going to the egr vacuum solenoid. Also has a larger vacuum line from the bottom. Without actually checking the system myself, this would be my best guess. There should be a part number right across the top of the modulater. Starts with and "8", 10 digits long.
Originally posted by DevilDog Unfortunately your independent does not know how the egr system works. Or he could simply check the system and tell you what is wrong. The proper procedure involves using a vacuum guage. If you already cleaned the egr passage and the check engine light still comes on. The your problem is probably the egr vacuum modulator. It's the round vauum device just before the egr. It has two vacuum lines into, then one going to the egr vacuum solenoid. Also has a larger vacuum line from the bottom. Without actually checking the system myself, this would be my best guess. There should be a part number right across the top of the modulater. Starts with and "8", 10 digits long.
DD
Where are you located DevilDog? I'm a former Naval officer so we have something in common.