My Toyota RAV4 has the following Issues:

1. Rattles (like grinding) when accelerating from 1500-2000 RPM (varies to even 2500RPM)

2. Poor Fuel Economy for a 2.0L i4

3. Sometimes almost looses "fire" (stall) when I want to accelerate in the mornings (after warming it up).

My Kazeem drove it and serviced the injector nozzles and told me all is well but IT ISNT :


So, I bought a Car Diagnostic Reader, courtesy Jumia Black Friday.

I scanned and this came up.


P0401
EGR Recirculation

P0141
02 sensor Heater circuit bank1 sensor 2


P0325 Knock sensor 1 circuit bank 1 or single sensor

cc: Gazzuzz, radautoworks, nurey (ORGAMYFARMS , Kingreign, et al

It means your RGR recirculates small amounts of exhaust back into the combustion chambers of the engine of your BMX bicycle.

Kingdemu:
It means your RGR recirculates small amounts of exhaust back into the combustion chambers of the engine of your BMX bicycle.

EGR

So, what's the solution?

naijadrivablog:




EGR

So, what's the solution?

Tell your panel beater to check if you have a clogged EGR passages on your BMX. Check for a faulty EGR valve. Check if the EGR temperature sensor on your BMX is covered with carbon and clean it.

naijadrivablog:
So, I bought a Car Diagnostic Reader, courtesy Jumia Black Friday.

I scanned and this came up.


P0401

P0141
02 sensor Hester circuit bank1 sensor 2


P0325 Knock sensor 1 circuit bank 1 or single sensor

cc: Gazzuzz, radautoworks, nurey, Kingreign, et al

How much did you get the scanner on Jumia

naijadrivablog:




EGR

So, what's the solution?

The person wants you to give your car specifications, that's why it's refered to as BMX bicycle.

naijadrivablog:




EGR

So, what's the solution?

Good day folks. Pls do me a favour and go to the nairaland thread below and vote for me by mentioning my username (KINGDEMU) as a comment. It's a giveaway for a car scanner. Make una help me because of God. Thanks

https://www.nairaland.com/6242597/mr-t-milex-carquest-rad-auto/3#6242597.103

So, from the codes, I deduce that three sensors are bad (hence poor fuel economy):

1 Knock Sensor

2. Vacuum switch : I noticed that the one in my car has ONLY one inlet from the EGR modulator; instead of one hose each from EGR Valve and EGR modulator.

I serviced the EGR modulator and EGR valves with Carb cleaner and it was blocked a little (carbon blocked the hoses) but the P0401 still comes up. I went to RAV4 forums and found out that the VSV (vacuum switch) could also cause that code, so I investigated further...

See what I found (pic 1) vs what it should be (PIC 2). Notice that my video shows one hose from EGR Modulator connected to it. the other pipe from EGR Valve is not connected anywhere.

02 heater sensor (downstream) is bad. Though I discovered that my SUV's cats where not in place (probably stolen in ApApa), the 02 sensor is bad too.

Do you advice me to buy Cats and the bad sensor? PR just buy the cats only? I may just employ Gazzuzz here to sell that spacer 02 sensor, of e go work

!

Promxy94:


How much did you get the scanner on Jumia

. Check Jumia .10k


Gazzuzz the Mercedes Benz 190E Dinosaur MOnk, come here.

Update: For the KNOCK sensor code, I asked my Kazeem to trace the sensor behind the engine and he found it that the wire is not connected to the knock sensor (probably eaten by rats).

He connected it and I drove for over 30kms, no code popped up!

I advice every car owner to buy a Car Scanner. Someone here on Nairaland who owns a mechanic shop at Kubwa asked me to pay N10k to scan my SUV



Again, after fixing the knock sensor issue, the 02 sensor (downstream) code appeared again (remember, my SUV has no catalyst).

Finally, the vacuum switch, which has one inlet of hose was found to be blocked (the other hose outlet). My kazeem advised that I block the hose from the EGR since the other inlet (connected to the EGR modulator) is the only functional hose.

I am not comfortable with this, I will buy the VSV switch and replace the old one.

Lovely DIY, thanks for the update.

Next item on the agenda is to understand your fuel trims and whether the gas consumption is adequate or excessive.

For the P0401 solution, the broken VSV is replaced + I got another Cold start sensor.

I even priced a catalyst and they said N10k last Buying it soon.

Pic 2 & 3: See connected "cold start" sensor vs the bad one on my hand (we don sandpaper am before)

naijadrivablog:
02 heater sensor (downstream) is bad. Though I discovered that my SUV's cats where not in place (probably stolen in ApApa), the 02 sensor is bad too.

Do you advice me to buy Cats and the bad sensor? PR just buy the cats only? I may just employ Gazzuzz here to sell that spacer 02 sensor, of e go work

!

Finally, I changed the 02 sensor B1S2

I drove for over 50kms and no more P0141 code and my mpg is better!

Remember that my SUV has no catalyst, what my panel beater did was to pass a straight pipe on the "centre port, with round holes punctured on several points on it - to create a type of "back pressure".

Instead of the hot gases rushing all out to pass through the downstream 02 sensor, the holes tend to reduce the flow. The only discomfort (if you like) is the port makes noise when you speed up.

aieromon:
Lovely DIY, thanks for the update.

Next item on the agenda is to understand your fuel trims and whether the gas consumption is adequate or excessive.

what does -17% means in long fuel trim?

almsofgold:
what does -17% means in long fuel trim?

A negative value means the engine is running a "rich" air:fuel mixture and the fuel being supplied needs to be reduced.

Read more at https://www.mechanic.com.au/news/understanding-short-term-and-long-term-fuel-trims

Is your SUV 1998 Dragon xb trim,with superturbo?

Kingdemu:
Tell your panel beater to check if you have a clogged EGR passages on your BMX. Check for a faulty EGR valve. Check if the EGR temperature sensor on your BMX is covered with carbon and clean it.

naijadrivablog:
For the P0401 solution, the broken VSV is replaced + I got another Cold start sensor.

I even priced a catalyst and they said N10k last Buying it soon.

Pic 2 & 3: See connected "cold start" sensor vs the bad one on my hand (we don sandpaper am before)

After doing that and changing the VSV, the code still came up. I had to change the EGR Valve and vacuum modulator.

aieromon:


A negative value means the engine is running a "rich" air:fuel mixture and the fuel being supplied needs to be reduced.

Read more at https://www.mechanic.com.au/news/understanding-short-term-and-long-term-fuel-trims

thanks bro