I'm a new RAV4 owner (and new to this board as well). I just recently bought a 1999 RAV4 through a dealer that has been quite helpful -- didn't even bat an eye when I asked to take that vehicle and another in for a pre-purchase inspection and he's been quite helpful. The RAV4 passed a pre-purchase inspection except for some oil in the sleeves around the plugs. The dealer had a mechanic that took care of it for me for a good price. I know in most cases the dealer is suspect, but this guy has been quite helpful, so I don't think he has ulterior motives and has been completely up front with me about everything along the way.

Now I get a couple warning lights. Sometimes I get a blinking "Check Engine" light that goes off after a few flashes and it seems that it takes about 30 miles of driving, throughout the day, after the light has been reset, and it'll go on permanently. When we've checked it (we being the dealer I bought it from and I), the error codes said that the fuel mixture was too lean and that there were random misfires on cylinders 2 and 3. I'm not sure, but I think my gas mileage is low, too (but that could me my imagination). I don't have the actual error codes. Last time it threw those codes we replaced the plug wires and he swapped the coil for plugs 2 &3 to see if that would work and about 30 miles or so later the light came back on.

I really don't want to have to take this in to an actual Toyota dealer or to someone else, since this dealer gets good pricing from his mechanic on the work he does, so if possible, it'd be just great to get an idea of what to check or what is likely the issue so we can get it fixed quickly.

Any ideas on this? Could the sensor warning for lean fuel be related to the cylinder 2/3 misfiring?

Any help would be appreciated!

Thanks!

Is this the wrong place -- or is there a better place -- for technical questions about a RAV4?

This board is very slow. Not a lot of activity. Sometimes a few weeks goes by before anyone answers a post.

A lean fuel mixture will not yield poor fuel economy but a misfiring cylinder will.

You have already replaced the coils and the plug leads to the cylinders in question so they should not be an issue.

Do the codes still indicate a misfire on cyls. 2 & 3? If so have you looked at the plugs? Has the oil leak around the plugs been stopped? Are they oil fouled? Could the pooling oil around the plugs be shorting the spark discharge to ground?

Based on what I've read about your symptoms, it remind me of the same problem I am having on my 1996 Acura 2.5 TL. Although, we're talking about Toyota and Acura - but the mechanical concept is the same, regardless of manufacturer. I recently plugged in an OBDII scanner in my car and a code (DTC) came up as "Cylinder 4 Misfiring". So I searched on AcuraForum...and was told that my Valve Cover gasket is leaking. That's why you see some motor oil in the sparkplug sleeve (tube). Which was true, when I removed the sparkplug and saw some oil around it. You stated that the mechanic took care of the problem for you - but I don't think he replaced the Valve Cover gasket. He probably just changed your sparkplug and maybe the sparkplug wires. If so, that did not solve your problem after 30 miles of driving. That's why your "Check Engine" light kept re-occuring; because the problem still exists and the error code is being stored in your car computer (ECU).

My suggestion is to remove the sparkplug in cylinder 2 & 3 or whichever ones that the scanner indicated as "misfiring". Take a look at the sparkplugs and see if there's any oil around it. If you see any traces of oil, that means your gasket is worned out and need to replace. I did buy a Valve Cover gasket kit for my car about two weeks ago. Haven't got a chance to work on my car yet. I did have the "Check Engine" light on my car came on about a month ago; but it was strange that it went away on the day I received my Auto Scanner and it's been off since. I got the scanner on eBay for $37. It's an orange color scanner OBDII. The seller ID is "mechanic_doctor". Just to be clear - I have no affiliation with this seller. I was satisfied with the scanner I got from him. As for getting the Valve Cover gasket kit I got for my car, I bought it from...www.autopartsplace.com. Again...no affiliation with any of the websites where I get my parts from. I am just being a wise shopper for auto parts and try to get the same or comparable parts at a cheap price. What I liked about "autopartsplace.com" is that they offer FREE s/h for order $50 and over. As I used to buy from www.autodoctorparts.com for many years; until they raised there minimum to $100 for FREE s/h. Just be a smart and wise shopper for auto parts.

Don't mean to brag...I am not a certified auto mechanic, but I have learned the skills for over 10 years - from reading a repair manual and actual skills/tips/tricks learned from my uncle [master mechanic - Honda].

Good Luck in getting your problem fixed. If you need any further help - I'll try to help you the best of my knowledge and skills. You can repost on this forum.