Mechanic Misdiagnosed P0300

4Runner is a 2002 with 344K miles. Had the spark plugs and head caskets replaced a year ago. Now a fuel pump and fuel filter.

Had the CEL come on and with a cold start would idle rough. After a few minutes it would seem to subside. While driving it was OKish, and then upon acceleration would be slightly hesitating. Checked with the ODBII scanner and it was code P0300, took it to a shop and they said it was the fuel pump and filter. OK done.

Picked it up and next day it had the same issue. Checked with the ODBII scanner and now it has added the P0304 with the P0300. Random misfire and #4 Cylinder. Took it back and now the shop is saying it is the Fuel injector on the #4 Cylinder.

After reading some posts about these codes and similar issues, it could be a lot of different things. Now the shop does have a professional type of ODBII scanner, and can read a lot more information then I can. But shouldn't they have done a compression test first and then a leak down test second?

I am not trusting this shop and I do not have the tools (testers) to DYI. I live in a small town in the desert and these guys are the only shop. Another shop would be 60 miles away. I am mechanically inclined - but can only do so much. My fear is a blow head casket.

 

Did the same shop do the headgasket work? A good shop would have compression checked and leakdown tested the engine. You can swap components over to see if the problem follows specific parts like if #4 is missing you can swap injectors with another and see if the misfire follows or the same with the coils. It sounds like this shop isn't very good at diagnostics and are just throwing parts at your Runner. How do they know the fuel pump was bad? Did they check fuel pressure?

 

They said they did a fuel pressure test and that is why they replaced the fuel pump and filter.

I am having do the compression test and leak down test tomorrow.

Thanks

 

so the shop did a compression test and leak down test and said it was the #4 cylinder fuel injector.

I drove it home and swapped the coils on #4 and #5…
Rough start and idle…checked codes…now I have P0300, P0303, and P0306. ??????? Totally confused. Any help would be greatly appreciated

 

So, I bought this vehicle from Larry about two months ago. He mentioned the CEL might come on due to an Evap code. I’ve been chasing down different codes. Replaced charcoal canister for evap. Had a 170 code and replaced MAFS. Now I have a PO303 code. As a result I came across this thread. I wish Larry would have been upfront with me, but my main concern is getting this 4Runner fixed, as it is my daily driver.

Any information or help would be great. And, Larry, if you found the problem that led you to sell this 4Runner, please help me out and share any information you may have found.

 

I found the answer from m one of Larry’s other threads. Looks like a head gasket ended up blowing and he used a head gasket leak sealer and sold out to me a week later.

 

Wow

 

Yeah. Super bummed. I’m a single father and a substitute high school teacher. I need to find a reputable shop, in my area, to do the needed repairs. Any advice is greatly appreciated.

 

If he didn't mention the head gasket, what a scumbag. Sorry you got the short end. Hope you find a good shop.

 

Thank you Neguem. No mention of the head gasket. I texted him about it and he responded saying that the head gasket issue was speculation and that he fixed it by replacing a spark plug. I’m just so tired of people out there taking advantage of others. We are all only on this small blue ball in space for a short time; we need to help one another. I hope the seller has a change in his heart and learns something from this if only for the sake of future persons that the seller may have interactions with.

 

Here is my comments and his short response from today regarding the OP here and the head gasket.

 

If they misrepresented what was wrong and you can show you asked, all these threads prove they were well aware and did not make the sale in good faith. Not a lawyer, but I would screenshot things now and talk to a lawyer where the purchase was made.

 

Larry sounds like a great guy.

 

@Lost Woods, this is a matter of human decency, or the lack thereof. I appreciate your support. The bottom line is going to be getting this fixed so I have a reliable vehicle to drive.

 

This was his FB Marketplace add.

 

I should have walked away when I went to buy it based on the fact that, talking in person, he told me that he was retired and he was selling it because he bought a jeep.

 

I just hope I can save of the money to fix it so my daughter and I can go on the adventure we were planning for this Summer—the last Summer we have before she goes off to college.

 

I wonder if replacing the engine is the better investment at this point, with 350K miles on it. I don't know. Would cost more for sure.

 

That is the crossroad I have found myself on. I’ve heard conflicting reviews with regard to remanufactured engines. From what I understand, to have that done, with a reputable mechanic, is $8,000 to $10,000.

 

Look at JDM. That's what I put in my van. Should save a couple grand anyway

 

It is probably no consolation, but if Larry bought a jeep, he has plenty of Karma headed his way.

 

Or used. There are a ton of used ones in CA on car-parts.com. Or buy a new 4runner, because its gonna cost 5-6K to fix no matter what. Maybe more in CA.

Personally, I will never trust a rebuilt engine again unless I know the person rebuilding it and know exactly what did and didn't get fixed. i got screwed buying a van with a supposedly "rebuilt" engine, and had to replace the engine 6 months later. Grrrrrrrr. But I went JDM, the engine and installation cost me another 4 grand in addition to the 4 grand I paid to buy the van.

 

Timmy! I’ve been watching a whole lot of your videos. Since day one of getting this 4Runner, I’ve been doing a lot of odds and ends myself. I’ve replaced all of the front suspension parts, radiator, and various other parts previously missing. In addition to upgrading the radio so as to have front and rear cameras. All in all, including the original purchase, I’m $14,000 invested in this. Starting over with another 4Runner sounds like a bummer—and another roll of the dice. I’m bitting the bullet and getting a Jasper reman. A whole engine swap is a bit beyond my level of expertise. So I’m having it done by a shop which offers warranty. I’ll be broke but I’ll have a “like new” engine.

 

All my buddies have moved out of state over the years. I watched your video on the Yota1 engine swap. It looked great. It appears the shops around here only want to work with Jasper engines. The engine is running me $5500.

I had looked up Yota1. They appear to be 6 months out for an engine.

 

Than you. I hope it works out well, too. I used to have lots of buddies to wrench with over a decade ago. If I actually had a garage I might do this on my own. Alas, I have a small carport, with 12 inch red pavers on a pitch, for a workspace. I’m a renter. Thank you for the well wishes. It’s too bad you’re not closer to my area. Have a wonderful day, and thank you for your support.

 

Yay, Timmy's here!