97 Avalon engine miss

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163
Location
Florida
I have a 1997 Avalon 3.0 eng. that has a miss that happens around 45-55 mph. Tere are no codes showing up and the tech thought that it was the transmission but two tran guys say NO. I don't know where to ture next. other than this the car runs great. Has anyone else seen this problem in a Toyota?
 
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Messages
14,732
Location
Central NY
Does it happen at part throttle cruise only? IE - if you get on the gas a little to speed up, will it still happen? Part throttle cruise "missing" with no check engine light. Dealt with that for a year. Turns out it was a bad DFPE sensor causing the engine to always run a bit lean.
 
Messages
169
Location
Kansas City
I always check the simple things first. A 17 year old car can be a vacuum leak candidate. Check for underhood rubber that appears crumbly, cracked, split.
 

gotnogunk

Thread starter
Messages
163
Location
Florida
Yes this is exactly what happens. Sorry for my ignorance but what is a DFPE sensor and where is it located. THANKS
 
Messages
8,598
Location
Florida
Originally Posted By: gotnogunk
Yes this is exactly what happens. Sorry for my ignorance but what is a DFPE sensor and where is it located. THANKS
Typically you dont have DPFE sensors in Toyota engines. A DPFE sensor is used to determining how far an EGR valve is opened, by putting a orifice in the exhaust supply tube, and measuring pressure drop between the 2 sides of that orifice. Usually what Toyota does is put an EGT sensor upstream and downstream of the EGR valve, and measure temperature change. Anyway, do you know the age of your spark plugs and wires? Also, a 1997 Toyota 1MZ-FE engine may have special spark plugs, and should only be replaced with what Toyota recommends. My dad would get 60,000 miles from those odd spark plugs in his Lexus ES300. When did you last clean the throttle body and MAF? Those easily cause a problem. Is the PCV valve original, or has it been replaced? It can cause the engine to run poorly if it hangs open. Expect the grommet to be brittle, and require replacement when the PCV valve is replaced. I only recommend OEM PCV valves and grommets. Got any vacuum leaks? Hopefully you don't. Typically if your car is that age, plastic vacuum devices will shatter, even if you cut the old hose in half and peel it away from the plastic part.
 

gotnogunk

Thread starter
Messages
163
Location
Florida
Thanks to all for the advice. I agree with you and have tried all your suggestions in the past. I think miller 88 was correct ( I hope, new sensor on the way) I removed the DFPE and cleaned the EGR reinstalled and it made the problem go away so I will replace with new when it arrives from Rock Auto. I hope this will fix the problem.
 
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