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david craig
david craig, Auto Mechanic
Category: Toyota
Satisfied Customers: 915
Experience:  owner/mechanic at 3D Automotive
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Story - many obvious parts already replaced ... it has

This answer was rated:

Long story - many obvious parts already replaced ... it has intermittent rough idle, and rough response to acceleration which is not temp depemdent.
JA: Is the rough idle intermittent or consistent?
Customer: Intermittent
JA: What is the model/year of your Toyota?
Customer: 2002 sxv 2.2lt
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: have replaced oxygen sensor, temp sensor, coils all vauum lines and air/fuel lines pcv valve filters in tank and under bonnet ...
JA: Anything else you want the mechanic to know before I connect you?
Customer: when checking spark plugs, the one cliosest to the coli packs was slightly coated with a rust looking substance where the others were not

Hi Im David, thanks for visiting the site. have a back pressure test done to check for clogged cat

Customer: replied 11 days ago.
How is that done?

take the front o2 sensor out, screw the back pressure gauge fitting in its place. start the car and let the idle settle. it should read no more than 1. then rev engine to 2500 rpms and the needle shouldnt move.

were you able to do a back pressure test?

Customer: replied 9 days ago.
I am going to the mechanical engineer tomorrow for a compression test to rule out head gasket, and inspect the catalytic converter while there.

ok. please keep me updated

Customer: replied 9 days ago.
Compression test, cooling system pressure test, and catalytic converter all checked out ok
Spark plugs however, although only 18 months old (so not formerly suspected), were arcing inside the caps and had severe burning on the ceramic. Replaced those - so far so good.

glad to hear it, but when you replace coils spark plugs should ALWAYS be replaced with them in a rough idle situation as the rough idle will directly affect the plugs.

please accept the answer and leave a 5 star rating for me if you were satisfied with my assistance. its the only way that i get credit for my help. thank you and have a great weekend.

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