rmique3152

Please help! My 2011 GX460 98k miles hesitates when you accelerate or in a limp mode but no check engine light. Replace spark plugs, MAF sensor and cleaned throttle body but still not working right, when in the highway it seems to work a little better but time to time you will hear the engine changes (shrudder and hesitation).

JonGX

coolsaber

what type of gas are you using?

Usually most things of this nature would trigger a CEL, but phantom issues will be hard to pin down.

Also you replaced a ton of parts, some electronic. Can you verify you replaced those parts with genuine Lexus/Toyota or at least Denso/OEM (not the this part is an OEM equivalent garbage). Toyota vehicles need OE (from the dealer) or OEM (verified Manufacturer part that is identical to the OE part but not in a Toyota box).

rmique3152

JonGX

to clarify - was it running rough BEFORE you changed the plugs and MAF sensor or did you replace those and then it wasn't running well?

are your spark plugs gapped properly? what part number did you use?

rmique3152

coolsaber

While this is only a guess, I`d say you need to get rid of the Advance Garbage and get some OE or at least denso NGK (most parts from Toyota) parts for MAF and spark plugs. I dont have alist of the OEMs but i assume someones got to know. If you have your old bits find the original Lexus MAF you took out, maybe clean it with some proper MAF only cleaner, let it dry complelty and reinstall and see. The plugs need to be the original type as well, and those you can pick up from any NGK seller (AAP and Az sell them if you want them now or theyre easier for you, sometimes come with rebates) or Rockauto/Az

rmique3152

coolsaber

What was your rationale for switching MAFs, u didnt mention a code then, what makes you think the new MAF would throw a code?

Im trying to say the following:
It depends on the programming of the vehicle and how out of spec those parts are. If your initial problem was hesitation, that isnt really a code unless it was a misfire. MAF sensors will usually throw a code, but there have been times when the threshold to throw a CEL has not been met. The golden rule tho with toyos is that electronics are a a finicky thing, and usually they need to be in line with spec.

Could have been a bad batch of gas, or vacuum leak etc. I would strongly advise just throwing parts at that problem. the spark plugs are a line item but even then they need to be inline with the original brand spec, ie dont through champion sparkplugs in the motor, its probably not gonna run right.

Short Form:
1) clean the MAF per protocol
2) verify spark plugs are OE type from either NGK to Denso

downshift1

I've seen a bunch of bad / clogged injectors lately on 4.6 engines. Not the kind of clog you'll get out with a gas tank additive.

John00

do you have an obd2? hook it up and check the values. look for codes 1st, then use something like torque to check all the measurements when this happens.
one possible culprit could be the throttle body. had to change mine like at 80 or 85k
also, some parts are covered way into the high miles, by fed law on the fuel/emissions system some parts have to be covered longer

Acrad

Is this something you are seeing in the shop?

I haven't really heard anyone talking about this on the forums or GXOR.

downshift1

I've had it happen in my 11' with 96k, I just had the injectors done on a friend's tundra for a weird random shaky idle at 76k that the dealer couldn't solve.
A friend at the TMNA tech line told me to have them cleaned. Ended up 3 of mine were dripping and reduced flow in almost all of them. He had two dropping and same reduced flow.

I've got another tundra to look at this weekend with a shaky idle also.

If you've got higher milage a good high pressure injector clean probably wouldn't hurt.